3rd nap help!!!

We are getting into a great schedule these days... and the first two naps of the day are so predictable and she falls asleep so quickly. The third nap however is SO hard to get her down for... Ive tried stretching the time between the second and third to help - she was super busy between them today and still no luck. Why won’t she sleep for her third nap!!! When she finally falls asleep it’s so close to bedtime that I can’t let her nap long or she won’t go down for bed... anyone else struggling with this?