As a CG , my guess is James that your wife suddenly realizes you are no longer there to “support” her and sadly she sees the child as an obstacle to her gambling.
CGs don’t want to be tied down in any way when we are in the “active phase”.
Having responsibility for a baby would seriously “cramp our style”.
Ignore her threats. Look on them as “the sting of a dying wasp”! They mean she is feeling trapped. Do what is best for your child and yourself. Odaat!