I have an 8900 and my gf has a pearl. Can i purchase a charging pod for my phone and and also be able to charge her pearl on it as well? The main worry i have is if the power between the two is different, and if so how will it affect her phone?

I can't say for certain but I doubt the power requirements would be different. I also doubt that a Pearl and an 8900 would fit/work in the same charging pod. Best bet is to look at the part numbers for the pods for each model and see if they're the same or not.