You can't have too much time in between breeding. They can become hard to get pregnant. It will not do anything to the udder or harm to the female if you choose not to breed. If you wait 2 or 3 years, she may or may not be able to get pregnant.
Just to elaborate on what ksalvagno said: you do not ever have to breed or rebreed a doe. Many people keep does and never breed them. But, if you wait years and then try to rebreed it may be harder to get them pregnant again.