while

hello ,i would like pls to ask about marriage ..my situation is that ive been in an unlawful relation with a muslim girl who is older than me we live in diffrent countries and we see each other every almost every other month..i want to make this halal and marry her but iam not sure if this will be the mother of my children that ill commit all my life to her and she also is not sure although we both love each other but we have many obstcales (like living in diffrent countires ..) is it a valid marriage to marry her without knowing for sure that ill be with her all my life ..i have no intention to leave her now ,she is aware of that .she above 30 years and didnt marry untill now and iam 25 so we ll safe each other from commitin g haram..also iam intending not to tell my family ,although they know about her as my girl friend but they are opposing the idea of marrying somone older than me .can this be a valid marriage?