Third party support is no longer allowed for settlement visas Michael.
Your wife doesn't need funds of her own - if your mother is solely sponsoring her - but if your wife had a job, then that's one reason for her to return before her visa expires , and this is one thing you need to convince the Embassy that she will, so the more reasons you have the better.
As for stating that she will be visiting your mother, don't try and hide the fact you're married. It's probably best being honest about it. Tell a lie - wave your visa goodbye.
, what you put a visa application could affect a future visa application decision.
As for using a lawyer, no idea, because the Embassy will make a decision on the information you supply or your lawyer supplies.
It's worth trying because of the low cost application fee and good luck