On looking into this idea further, I think I did find a legal issue, unfortunately for you.... one can't exchange into a house being sold by a relative...
1031 Exchange - Frequently Asked Questions on 1031 Exchanges
Do you have any brothers or sisters who could buy in? Anything that was a straight purchase should fly.
Or what about giving your Mother half your equity via a deed and then having her subsidize you for one or two years-say 30K worth? At some point, you could buy her back out again.
A good RE lawyer should be able to come up with more ideas. That lawyer you talked to might have just been jealous. Most people don't have willing and able relatives!!!