Is it permissible for a woman who performed Umrah in Ramadan to shorten her hair at a women's salon in Riyadh two days after her return, and what are the prohibitions if that is permissible?

Shortening the hair of the head is one of the obligatory rites of Umrah (definition), and a woman does not exit her state of ihrām except by it. There is no harm in a woman delaying the shortening of her hair until her return to Riyadh, but she must avoid the prohibitions of Ihrām until she shortens it.