L.N.
Couple of things come to mind. One is to put her in a pullup at night and eventually she will be dry. Once she is dry a lot of nights in a row, try it without. At one time we were able to use the same pullup several nights in a row til it would fall apart almost. That's when I realized we didn't need it anymore. :)
Also, try putting a potty in her room at night. Tell her it is okay to get out of bed and go potty. You'll have to go the pullup route here too, unless she can diaper herself...lol
Also, as a tip, one mom suggested to put sheets on differently. First a mattress pad, then a fitted sheet, then a plastic fitted sheet, then another regular fitted sheet. That way you can strip it off the bed in the middle of the night if need be and the new fresh one will be dry underneath. Also saves the mattress.
Good luck.