Struggling with naps

My daughter will be one tomorrow, and we are struggling with naps big time! Her wake windows are now about 4 hours. Today we woke at 7am, and took a nap at 11am, but only slept until 11:45. She won’t be tired again until about 3 or 3:30, but that’s too late for her to take a nap. We found out that if we let her sleep past 3pm she’s very difficult to put down at night. She currently sleeps 7pm-7am, which we don’t want to mess up. Any advice? I feel like keeping her up from 11:45am-7pm is way too long. She used to take two naps when her wake windows were shorter, or sometimes one big nap mid day which worked out. The past week it seems like she just won’t sleep during the day! This 45 minute nap in the middle of the day is not working out!