My older daughter had extremely severe reflux...a couple of thoughts. She probably wants space between the solids and her bottle because her tummy is full and she needs some time to digest. Babies figure out very quickly what makes the reflux worse (a full tummy) and adjust their feeding accordingly. She's also small and is getting calories from her solids, so probably doesn't need as many from the formula and will cut back on that. Kids are good at figuring out that their bodies need a lot of times, so as long as the pediatrician isn't worried, I would just follow her lead and get what formula in her you reasonably can. The sleep may just be a developmental issue, she's working on some skill or working on teeth. Good luck and hope you get some more sleep!
Updated
BTW, just read the other moms answers and they are totally right about her needing formula over food. I was going by my own experience of having a baby with such severe reflux that she didn't want to drink anything, because it all just came back up. I had to start solids on the early side because the heavier food was all she could keep down well. I focused on cereal, and made it watery with as much formula as I could get away with to get max amount formula in her. If your daughter was doing well with the bottle before you introduced food, sounds like you might want to back off food again for a couple of months and focus on formula. Take care