She may be fine with you wearing the female pyjamas she bought for you, but the whole "I'm a crossdresser" discussion is a completely different kettle of fish. She is obviously OK with you wearing femme clothing around the home, but how will she react to hearing that you have been hiding a secret from her may be very different.
Crossdressing may not be a problem for many wives, but deceit is always a problem for all wives.