How about some reusable ones? They have some lovely designs and look more like pants than nappies. Have a look here for ideas. Depending of how much she wets in the night, we used reusable pull up pants - Motherease Bedwetters - which wrked well.
Do you put her on the potty just as she is going to bed? Try putting a bed mat (think they are made by pampers) under her as well as having the usual plastic sheet on the mattress. Let her go to bed without any nappies.
when you say she is wet in the morning is that wet in a nappy? you could try no nappy and those pampers caremat things to stop the bed getting wet, my girls were always wet when they had a nappy on but when i removed the nappy they were dry
thing is with my girls who have autism and were in nappyies until aged 5, they conected nappies with wee's, so for them no nappy on meant they didn't wee, also if she is wearing a nappy in bed if she wants a wee she may not be able to get the nappy off