Help Deciding On Job Offer

Take it and re-evaluate how you feel in a year, while continuing to research the pay for similar roles.

A bird in hand is with two in the bush.

Here are my thoughts, work life balance shouldn't mean anything the first 2-5 years of your working life.  If you are working 40 hours a week at 22, you are not learning anything.

55k for a year-1 offer is fine if not a little low.

If I were you I would ask for a 5k bump plus 10% bonus.  Having raised 100-300mm of equity it looks like you are in a good place to be.  If they do not go for the increase in comp, you can always ask how the position scales, as in how long does it take to get to associate, sr analyst etc.

I know a handful of folks that have hired recently in Toronto for junior talent. Like many places it's incredibly competitive and top shops are paying ~$125k all-in for AN1 (think Brookfield, Cadillac, Kingsett).  Hours are likely ~60 (80+ during busy periods).  Great deal reps and experience working with high qual investment folks.  Even smaller shops are having to get up to ~90-100k to get the talent they want.

Ask yourself, if the family office is offering up such a limited comp level, is it because they don't yet trust your talents, or because they want to keep most/all of the pie to themselves?  Bonus is absolutely the norm in this industry and very odd they wouldn't reference it.  For taking a role in a small shop, with likely limited upside (keep things in the family), on a $100-300MM fund -- huge range btw -- they should compensate you at street level. 

DMs open if you want to chat but go get the $$ you deserve.  Unlikely to bridge a gap from $55 to $100k, so agree with the poster that said take the job (maybe aim to get them up to $70k) then hunt around.