Have you tried or do you play pretty hard with her before bed time? Also you did not say what time she is going into the crate at night...I know that Fiona did not sleep through the night until she was about 5 months old, she was still needing to go out to go to the bathroom somewhere between 3 and 5 a.m., so we started playing real hard with her before bed time and waiting to put her in her crate a little later at night, making her last outside break about 10:-10:30....She started sleeping and then became use to our schedule which is getting up by no later then 6, so now on the weekends she has to go/ or gets up by 6.....
At about 7 months we started leaving her out of the crate at night without accidents so it may take just a little more time. They all "get it" at a different pace. Even now though if I have to put Fiona in the kennel at night and then she gets up about 6 and does her business, she does not want to go back in the kennel and if I put her in there she will whine, they are just awake and ready to play after going to the potty and dont understand why they need to/have to go back to crate/sleep.....