1040X, when will it be available, really

I filed and my return was accepted, I then later submitted my childs return and it was rejected due to me incorrectly claiming them as a dependent. They had a 2nd W2 come in I wasn't aware of which increased their earnings. 

IRS wont except their return electronically because of this... Should I file theirs manually, then amend mine when it is available or wait for 1040X to amend then file theirs electronically?

 

technically I think my childs is considered filed on time due to a rejection.