Oh dear! What kind of mum would leave their son with their Dad? Has she got other problems besides, such as depression or mental health issues? Is she going through a mid life crisis?
This is what happened to me. My H left me without a good reason, said he was staying with a friend for 2 weeks and came home after a week to say he would try to work at our marriage. This time I put in all the effort and he didn't seem to be trying or telling me what the real issues are. It's pure guess work isn't it? He left about a month later, just like your wife! Have patience, it's early days yet! Don't expect her to come running back quickly and if she does then she's just yoyoing back and forth. I would be very cautious from this day on.
If she does want to come back then take things very slowly. Tell her to stay at her mum's and have a few dates together. Visit a counsellor together and make sure it's the right kind of counsellor as described in divorce remedy. I take it you're reading either divorce busting or divorce remedy at the moment? It doesn't just apply to couples getting divorced, it applies to couples in all situations.
Come back and chat whenever you want to, I'm here most days smile You will be on moderation so don't post loads until you get a reply to your last message. We won't be able to keep up smile Don't worry, you won't be on moderation for long smile

H47 me48
T22 M21
S20 - Got high functioning autism
3/2000 H admits to OW and moves out to live with her
11/2000 H moves back home
2/4/13 H moves out
H tells me he wants D 6/13, but now he can't afford to!