Felicia will be a familiar, and has the capacity for self determination. If you read the entries you will also notice that Felicia is consuming large amounts of Vis from her personal vis source- the season she did not she was only able to gain 1xp. She is being treated as a magical character, simply one with the capability to read (I'm not sure if the magical hands would have enough manual dexterity to write, though she could presumably dictate if she wanted to write a book)
If she is consuming vis, then that should balance out appropriately. Making her a Familiar would be a great benefit to learning also.
However...
Mind you that she is a Story Flaw. One I should use on you sooner or latter. If you make her a familiar, I feel obligated to generate a story based on that event and to play up the potential flaw in the bond. However, as a story flaw character, Felecia has a higher starting potential than most standard familiars.
Also, this may not work. Being a magical friend doesn't mean you have what it takes to be a familiar, just like someone being your friend doesn't mean s-he's your best friend, or your best friend being someone you'd be fine marrying.
You may very well end up discovering you 2 just aren't linked that way 
Fair point, I've been putting it off. But how does one stat a "normal" person? Isolde isn't a Companion, or a Grog. She's just an ordinary young woman, probably about 14 if my history holds up.
wait...
your fiance is only 14?!?
I know this is fiction and the middle ages, but ??????
The only difference between Companions & Grogs is the number of Virtue/Flaw points. How many do you really need and what are you looking at?
And at this late point, does she really need to be statted? Just some personality traits and minor notes should suffice.
and 14 ins not a "young woman". 14 is "teenage girl". I know this is the middle ages, but do you really need her to be that young?
No, no need. Was just going for verisimilitude, but I'm also happy (relieved?) to waive that in the interests of propriety. Hows about 17?
And I'll happily stick some traits on Antoine's page for her when I next get a few minutes. I have ideas for about 5 traits, which is unusual. Usually I'm hurting to find 3 to write about...
That works 
I've been looking into spell masteries for Lucas, and I was looking at Roberto's character sheet to get an idea as to what masteries would be good to take with what spells. I see that Roberto has taken Stalwart, Efficient, and Flex-(Parameter) as some of his masteries. Are these generally available? Because I'd love a few of those. But I thought only people in the Cult of Mercury could take those.
Here is a full list of Spell Mastery Abilities let loose in this saga. Some of them are experimental and never been used. We brainstormed them up a long ways back and decided to let them fly and see what works. There are a few that have special requirements, as you mentioned, but they are not as stringent as you imagine. According to RAW, anyone with the slightest Mercurian influence can take Mercurian Masteries. Reference Societates, the Flambeau section, for further details on this. Roberto is Mercurian, though not a cultist nor interested in any Mysteries. Virtues such as Flawless Magic, Mastered Spells, and (others I forget) are all that a character needs to qualify.
I wish I'd known that when I was making up my character. Some of those Mastery abilities are pretty darn nice.
ETA: I was just re-reading HoH:TL and noted that it says:
Does being a Mutantes necessarily mean that he's not a Mercurian?
Maybe and maybe not. Do you have any Virtues or Flaws that could be categorized as "Mercurian"?
None of the Virtues or Flaws listed as "suggested." I guess that's a bad sign.
I'll just have to get Roberto to teach some of those masteries to me. I can teach him Harnessed, Tethered, and Boosted in return. 
So I've been thinking about Companions lately, particularly as I made up Lucas's wife, Cecilia. It occurred to me that when I first joined this game, I didn't know exactly what to expect, and I picked a companion almost at random. Bashir is an interesting character, but very quiet and reactive - not at all likely to butt into a story or really have much in the way of adventure. Oh sure, he might go somewhere. But not in an adventurous way. He's just not the adventurous sort.
What's more, he's a doctor in a world where anyone who's important is getting magical healing (or at least magical healing help). That makes him, if not superfluous, a lot less interesting. True, he can brew some formulae. But those are mostly for other people to use.
All this is by way of preface of saying that I'd like to swap out companion characters. Bashir just really isn't doing it for me anymore. One idea I had, which I floated with Marko, was to play Cecilia as a companion. But I wasn't sure if that was a bit too much. After all, we have (had?) a Redcap as a PC. I wasn't sure if playing a Redcap as a companion was okay or not. (Then again, our PC Redcap is going on extended holiday ...) Marko said that I should bring it up with the troupe, so I am.
I should add that my feelings about Bashir are the same regardless of the decision with respect to Cecilia. I'd like to change companion character (assuming that's acceptable) whether it's Cecilia that I get to play or someone else. In the end, I'd like to get someone with the potential for a bit more adventure.
So what do people think?
I would remind you that Bashir nursed Roberto back to health after almost drowning
Buit I really don't mind, and if the troupe is fine with multiple characters then go for both. I do invoke the wrath of our fellow players to scrutinize the new character, since the HR's amp them up a bit.
I always reccomend that Companion characters be linked directly to your magus in the first place anyway.
As for Isolde and Antione, I suggest that she also be made up as a Companion character, her status as NPC means that anyone running a particular story can take over &/or reassign control as desired for story results.
I don't mind Cecilia being a companion; our last two Recap PCs were campanion characters as well, so the precedent is there. Bashir could be relegated to "Specialist Status" like our teachers.
Noted. She'll have to wait until I'm home again, then; with book and m not posting from a phone!
UnGifted Redcaps are supposed to be built as Companions. Core rulebook, p. 30: "Note that unGifted Redcaps are created as companions, and take the Redcap Major Status Virtue." HoH: S, p. 78: "Redcaps... have many of the same rights and privileges as magi and are usually played as companion characters."
I took a quick look at Cecilia, which makes me notice that Redcap LR is strange, and adds even more to their power (compare Cecilia to a regular companion, she's insane, and she's a well-rounded, non-munckin character).
As it is, a redcap LR of lvl 56, before discount, costs (56+35) 91 qpv. The same for a magus would cost (56+2*35) 126qpvs. There's no reason for redcap's LR to increase less sharply as age goes by, and this complicates things needlessly.
IMO, it should follow the same rules than magus LR, with a discount of 68qpvs added afterwards (this makes a LR taken at age 35-36 free)
I have no problem with that. I was just following the creation process as written.