What Tracy's mom told Andy about the Degas is true. You can buy a copy of many Degas statues. There are some available on Amazon for about 80 bucks.

Somebody I forget who, asks him about the statue in the living room and he mentions his wife inherited it from her father and that it was a real Degas. I think it was either the detective or the dr. So, that part was before the story of the movie.

I have watched Malice many times but I dont recall Tracy telling Andy about the statue. Where in movie did they do that? I know her mom told Andy about the statue.

Awesome! Thank you for your responses and research. I didn't think anybody would bother answering so this made my evening. It's the little things, haha. The relationship length and lawyer knowing the mother via the father make sense enough. The Degas still strikes me as odd but, like you said, it's a red herring and not a big deal. I enjoy the effort the writers took creating all the twists and red herrings.

SPOILERS
Good questions. I just watched the film about two hours ago and have seen it many times before.
I would suspect that Andy and Tracy were no more than 1-3 years married. I say this because they seem to still be like getting to know each other and they have awkward fights (like when she gets mad at Andy for "spying" when she gets dropped off by the lawyer.)
The Degas was used as a plot device, specifically to show Andy's discovery of the truth. It was also sort of a red herring in that it kept us distracted. Tracy told Andy it was a gift and possibly an original because she was torn about her father taking all the money and leaving her and mom. In other words, the Degas was sort of a twisted link to a loser father.
As far as the lawyer knowing about momI may need to watch some scenes again to make some connections
EDIT - there is another thread where someone suggests the lawyer knows mother because he may have represented mother and daughter when Dad got sued after he disappeared with funds.