If these female RINOs abstain, that leaves Romney as the wildcard. Let’s be pessimistic and assume that his hatred for Trump is greater than his love for country (not an unrealistic assumption)... that makes the confirmation a 50-50 split since Republicans control the senate 53-47.
This leaves Mike Pence as the tie breaker.
But if 3 Republicans abstain, that would leave the vote at 50 - 47 and the nominee would be confirmed.