I've not ever done 50/50--our custody arrangement was the standard EOWE, split holidays, summer vacation, etc. My younger son was only 1 yo when we started with custody. Yes, it was hard; ds1 wasn't too familiar with his dad and was very much a momma's baby. Those 1st few times, I put on a happy face and never, ever let ds1 know how upset I really was. (BTW-his dad is a *great dad* as well and loves his boys very much.) It didn't take long for me to see the baby (and his older brother) were doing just fine. They enjoyed their time with their dad, and being away from mom for a little while, and were glad to be back home when they came home. And mom was rested and relaxed and ready to be a mom again. :)
It will get easier to accept after a few times. And you really, really need to be okay with it. Kiddos can sense moods, tension, etc. and the more there is of that (especially at hand-off) the harder it will be on the baby. If you are okay with it, the baby will do just fine.
So many times a single mom just doesn't have time for herself or her friends, so take full advantage of the time your dd is with her dad. Find/ressurect a hobby, visit with friends, go to the movies, sleep(!), whatever. Take time for you. This is good for you and it is good for the baby.
Good luck!
mjaye--single mom to two boys, 18 and 22.