Its entirely possible but you will both pay stamp duty on the market value of the house you are getting - but it will be at half the normal rate as you are related. ( So long as partners/spouses are not involved- not your mother but your partner/spouse).
The up side though is that if the houses suit each of you you save on Estate Agents fees and you have the stamp duty saving so even if it costs you something, it is less than you would have to pay on the open market.
mf