Sleeping schedule

My daughter used to nap every 2 hours , now it's a nap around 11:30am or 12:00 pm and another one at 6:00 p.m ... she fights her sleep at night. She used to go to sleep by 9:30pm but now it's not until 10:30 or 11:00 . What should I do ? Its driving me nuts . I might have to bring it down to one nap or wake her up from her last nap early...