1) They aren't married - legally the kid is up for grabs. 2) She is unstable 3) Her living situation is questionable 4) She is unreliable 5) She just quit her job which makes her subject to go anywhere at anytime and technically, she can take the kid with her if she decides to.
Just to clarify.
"Let anyone who thinks he stands take heed lest he fall" 1 Cor. 10:12