H.L.
I know your a first time mom but unless you want to be rocking her to sleep when shes ten you better start letting her cry it out or you'll be rocking her to sleep for years to come there is nothing wrong with a baby crying right before they fall asleep its a sign of being tired and sometimes actually helps a baby settle down. Also she may just be discovering rocking back and forth in the crib and being more mobile and she may be enjoying this do you give her enough floor time to explore when shes not sleeping? she may only have a chance to do this when shes in the crib i would suggest letting her have tummy time and rolling time on the floor when shes not sleeping so she can get this out of her system. Babies sleep patterns and needs are constantly changing and you will find that just when you think you have a routine going she will change it for you.
Good luck!
From H.