Welcome!! And good job sticking it out with nursing this time around!
It's pretty normal to be worried about how much baby is getting... I see a lot of people fretting about it! It's hard to let go of that anxiety.

But it sounds like she's gaining really well and eating well. Trust your baby! She'll let you know if something isn't working.
As for patterns.... yeah. Patterns may come later. Or may not. They also like to continue changing things up every week. And not just with eating... with sleeping and play and preferences and food. My daughter still drives me a little nuts... one day she wants to eat a meal every hour and the next day she won't touch anything I put in front of her. So it's totally normal that she doesn't have any pattern! They go through growth spurts and they are developing so fast... everything changes day to day. Try to just go with it and trust that she is doing what she needs to do for that particular day.