My wife and I have been separated for almost a year and our daughter will not nap or easily go to bed at night for her mom. When she is with me, she naps great and I never have to fight her to go to bed at night. Her mom is convinced she hates her. Any help on what is causing this?
For the most part, this it totally normal. It's not an expression of 'hate' or 'dislike' - in fact it's in my experience more that the child feels comfortable enough to act out and test their boundaries.
How do you handle it? You have to find a routine that works. Dad has figured one out, Mom hasn't. The routines can, and probably should, be different - have the things Mom does for nap/bed and have the things Dad does for nap/bed. Once the child is in a routine, it will be normalized - but until then there will be some struggle. Accept it, be in a place where you can acknowledge that you will need to be patient with the child for a while until the routine is established, and most importantly keep your emotions under control.
It will happen, though; we had two children both of which had difficulty sleeping, and did go through extended periods of challenging bedtimes/naptimes. Ultimately for us we chose to stop napping earlier than many do; that's based on our child's needs, though, not based on difficulty with napping itself. We did figure out a routine that worked, and did that until each child was ready to not nap any more.
There's another interpretation of your daughter's behavior.
In my experience, children tend to act their worst with the adult with whom they have the most secure attachment. In my case, and possibly yours, Mommy gets the worst behavior, because Mommy is the primary caregiver.
This is not to suggest that you as the "not primary" caregiver are less than or in any way less important, just that for most children mommy is primary and daddy comes next.
If this is true for your daughter, she may be holding on to some stress that she felt in your care and letting it out when she's with Mommy.
Again, this is not a reflection on you as a parent or on you personally, it's something I've experienced with my kids and have seen others experience, when our children were very young.
In reality, I can recall my friend reminding me that my child let's it all out around me because they feel secure, and this was when my son was 9yo. So, it's possible that this pattern will persist.
One way too deal with the difference in behavior between mommy's and daddy's homes are to understand that children, by definition, are not consistent, and it doesn't necessarily mean anything about the way mommy and daddy independently parent or the quality of each parents' relationship with the child.
The only suggestion I have for a change in parenting, that you might try, would be to create a nap and bedtime routine that is the same for both homes. There's a possibility that having one routine for bedtime regardless of which home and which parent she's with will increase your daughter's sense of life being predictable, and that may translate into an easier bedtime for your daughter when she's with her mom.