Has your child got a UK passport?
Her husband being in another country may be conjecture if for example he had not been in touch for 4 years then she could file for presumtive death of her spouse.
Failing that she will have to go the Annulment route there being no divorce in the Phils.
In the meantime and with costs and your personal finances to take into account with your child registered she might apply for an interim visit visa this is mostly going to be a funds issue if you want to resolve it as quickly as possible. and cant go there
