Start making a calendar of your daughter's entire life. As you're able to fill in time you know she was with you, make sure and mark those dates. If you've archived pictures on Google Photos, this can help fill in dates. You want as much contiguous history going backward from today as you can. You want to show what you mean by "status quo." Not "well, I think we've had her about half of the time," actually come prepared with documentation. If you have a few pictures (and I mean a few - I'd say 8 tops), print those onto 8x10's paper and include them in a section of your parenting notebook. Maybe you could get it comb-bound at a local print shop or FedEx Office.
Start making a journal. DayOne is great if you have an Apple device, and I've found "Journey" to be wonderful on Android. Both will let you retroactively add entries. You shouldn't make things up, but you can add documentation to what a wonderful dad you are, and also include factual entries that pertain to your parenting time, including confrontations and conversations you've had with D5's mother. Again, this isn't a chance to go off on her. But if something she did was upsetting, describe the circumstance and just say "this was upsetting." Refrain from comments like "what a (you-know-what)."
Keep this current and just be ready to print and bind it when you go to court. Stay organized. Fill in the past with what you know to be true. Even "we went to Denny's for breakfast this morning, she got chocolate chip pancakes," or "she took her first steps last week." It's a powerful tool in showing not only that you're involved, but that you're paying attention to things that matter to your daughter.