J.,
There's a reason why the car seat manufacturers say to only use them in the car - it's because they can be unsafe in other situations - and the Consumer Product Safety Commission made them put that on their labels. My aunt works for the CPSC, investigating child injuires and deaths. She has so many stories to tell me of children that were hurt while sleeping in car seats out of the car (them toppling over and trapping the child, getting tangeled in the belt straps, you get the point)...
On a personal note, our cousin's 1 year old baby died a few years ago while napping in his car seat. The daycare provider thought she had strapped him in correctly, but she hadn't...One of the belt buckles wasn't clicked in all of the way, he slid down while napping, and the chest clip cut off his airway. The coroner said that he couldn't breath or cry because of this, and died within minutes. It was the saddest funeral I have ever been to!!!
I would NEVER place a bouncy seat or a car seat in a crib!!! The car seats can flip over easily, and the bouncy seats are designed to be used on flat surfaces only!
Have you tried swaddling your baby snugly? A lot of babies that young really enjoy swaddling. It might help your baby sleep better! Also, have you tried a bassinet? They are smaller than the crib and your daughter might enjoy it.
I remember having my daughter at that age, and having her sleep those extra hours was a real gift. Trust me, your daughter will get used to her crib. She'll start to sleep longer and longer. I urge you not to put her in a bouncy seat or car seat in her crib, it's not worth the risk.
There was a post similar to yours (with tons of responses) on Mamasource, last summer I think, if you can still find it. The best of luck!
M.