As a single woman, you can absolutely do surrogacy in Mexico. However, because all birth certificates are issued using the biological father’s name and the surrogate’s name, you will need a trusted friend or relative to be your sperm donor and to sign all contracts.  He will be the one responsible for retrieving the baby upon birth and completing the baby’s exit process to return to your home country. Later, you can have him relinquish all legal rights to the child and give you full legal rights.