It may be too late now -sorry I've just seen this question, but tell your Solicitor that your mum's going away. They may have things on their file that can be signed now and held until they're needed. Alternatively, they will just say well, we'll do it when she comes back. If they think things will need to be signed during the next two weeks, they can prepare a short Power of Attorney dealing specifically with this, where they could sign on her behalf (if the Mortgage comany will accept this). They'll probably just say things can wait till she gets back....