The divorce deal will be put to Parliament, which was always going to be the case. the idea that a trade deal and the divorce deal would go hand in hand was never a possibility and those peddling that nonsense need to give their head a wobble
There in lies the problem.
May held the election because she wanted a stonking majority, then she would've controlled (at least at our end) the agenda and had a sufficient majority to ram through Parliament whatever dogs dinner she liked.
She doesn't have that majority now, not only does she have hard and soft Brexiters in the Tory Party, she's got Scottish Tories now with their own agenda and of course the DUP, she's even got the odd remainer. Put bluntly she can't depend on her own party to support her version of Brexit.
Because of this May needs other parties, particularly the Labour Party. She has the numbers to leave, we are definitely leaving, there are overwhelming numbers for leaving now in Westminster and we are going to leave the single market, there is a majority for that as well, we will stay inside the customs union for quite a long time as a transitional agreement that's a given, assuming the EU will allow it (they are in the driving seat and goodwill is in short supply), but come the day that MPs troop through the lobby to vote on the leave settlement she'll need Corbyn trooping along side her (assuming she's still PM come the day).