I go for first class any chance I can get, even if it requires paid F, just because the planes always fly full and I tend to draw the 300# passengers in the seat next to me. You are in good shape in that department since your family can grab three seats across and the toddler doesn't make for a snug seating arrangement. I'd be content with Y if I knew I'd have my toddler or an empty seat next to me.

Another consideration, since you've got one person on the companion ticket, is that paid F is more reasonably priced since you're only paying the high price on one ticket, but you get the 50% mileage bonus which also counts as EQMs (for the two travelers). Again, that might not be a big consideration in your situation since you don't fly AS a lot, plus it would also mean getting your toddler into F also.

I think I'd price the toddler's ticket at full price, AS50 (15k miles to save $250) and a mileage award (which currently is showing 25k RT). Comparing all of those, I suspect the mileage award would be the way to go since, as beckoa noted, the full ticket will probably be north of $600.