You should see another attorney. Someone on Sajha had posted an excel file from USCIS showing 15-20 green card petitions from TPS status some time back. In USCIS website it clearly states that - you will not, by default, get a green card from TPS, BUT, you can get a GC from TPS if you get sponsored by a US employer for one, or get married to a US citizen.

The only catch here would be, say before obtaining the TPS your wife was out of status for more than 6 months. If so, then you would not be able to adjust status. Since your wife was in H4, that shouldn't be a problem.

Also, did your wife have just TPS, or TPS + EAD? Previous visa status gets overridden only if you had EAD, AND used the EAD to work. Just possessing TPS and the EAD card does not invalidate the existing visa status.

Consult a good immigration attorney. Good luck.