Sorry I can't help much. My twins are 14 months old, and while they've
been taking toys from each other for some time, they're only recently
getting upset with each other about it. For now, redirecting them to a
different toy is working for us, but that can't last as I'm sure you'll
tell me. I'm interested to see what experienced parents have to say.

I am in the middle of reading the book Raising Twins by Eileen M
Pearlman and Jill Alison Ganon that may be helpful. According to what
I've been reading, it sounds like your twins are learning about their
sense of self and what's "mine".

As far as one being jealous of the other's time with you, I've found
that sometimes one of my twins needs more of my attention than the
other, so I give it to him. Next week, his sister is the one who needs
more attention, so it evens out in the end. I think their needy time
passes quicker when I give in to it. The days when they both need more
attention are the days I'm really happy to see my husband come home
from work.