M.T.
Hi M.,
Please don't listen to the post below, many women nurse into and through their pregnancies. There are no medical recommendations against doing this, provided that you are having a normal pregnancy. Nursing does not take nutrients away from the growing baby - the growing baby doesn't get your breast milk.
I don't really know about the hormones causing diaper rashes in breastfed babies/toddlers, but if that's the case, I'd try to find a way out of the diapers. I would also take her in to the doctor and check for thrush, which isn't related to pregnancy but both mom and nursling would need to be treated.