I would probably look at eliminating the 3:30 bf, instead offering a good snack. This way she will be on 3 bf "meals" during the day. Can she hold out for her first bf in the morning until 7am? This would help you push the second bf and meals, which could help for when she's on 1 nap. When my dd first switched to 1 nap she was napping from 11-1, then she pushed it later and later, now at 2 years she naps 12:30-2:30. Eventually, when you eliminate another feed after that it should be the lunch bf, so that you are bfing 2x- morning and evening. If you do cut back on a feed it will be important to make sure it's substituted with a decent calorie snack, otherwise it could worsen the nws.
Also, you mention that she's not so interested in breakfast, it could be that she's not as hungry since her bf is 30 minutes earlier, offering the solids later than the 30 minutes may help her take more.
Have you started her on whole milk yet? That could help with getting extra calories into her during the day and may help with the nws.