if you have a communication problem by phone why do you not express your feeling by writing a letter to her. that will also be a proof as an attempts for saving your marriage.
if her parents are well settled why are they wanting monetary support from you ?
She may be attached to her parents.may getting all the emotional support she needs. and now she has twins and first delivery she will like to be with parents to manage new borns. ask her if she wants some more time to stay with parents for kids care.
no parents will willingly want their daughter life ruined atleast after the child birth as they know chances of remarriage is dim. they do not have confident that you will look after their daugher with love and affection. so they have apprehension send with you.