May is apparently a proponent of Sharia. That will not work out well.
No, she isn't. The stories that say she is stem from a hit piece that was deliberately written to try and discredit her, largely because the author doesn't like her conservative credentials.
It was spin - it managed to turn the fact that May instituted an inquiry into Sharia 'Courts' in the UK that was intended to make sure that they were not operating in a way contrary to British law into an idea that she supports Sharia. Exactly the opposite in fact - the intention of the inquiry was to ensure that any such bodies were acting in a way consistent with British law. If they were, fine (and that is entirely possible, if their rulings stick to certain areas of civil law), but if they weren't, they'd be shut down. She made a statement explaining that there were some principles in Sharia that match normal common sense, and that quote has been taken out of context.
She is not a proponent of Sharia. The most important part of the statement she made was that Britain only has one set of laws - "So there is one rule of law in the UK" were the exact words.