Has she been 'scolded' for doing a wee on the carpet, as that could be a reason why she is going on her bed.
You may need to take her outside for the opportunity to wee more regularly. After food, as soon as she wakes up, when she is sniffing 'with intent', during play, and every half hour in between, when she is not asleep of course. Make sure you wait outside with her until she does the 'deed' and give her loads of praise. If you catch her doing something in the house, pick her up and take her outside, do not scold her, she may have finished the wee, or you may have a stream as you carry her. You need lots of patience, and never ever rub a puppies nose in their wee.