Are these sentences correct?

1. I'm the youngest brother of your husband./I'm your husband's youngest brother.  Yes, both are correct, although the second one sounds more natural.
2. He told us that he'll take you and your children for vacations to Poland. He told us that he'll take you and your children to Poland for a vacation. ("Vacations to Poland" is understandable, but not what someone would say)
3. We were supposed to meet./We were supposed to know each other. Maybe supposed to get to know each other. We were supposed to meet is fine, but it implies either that it was supposed to happen but did not, or that it was destined. We were supposed to know each other would also imply destiny. 
4. If you need anything from the Polish department(??) (Yes, and a comma after department.) or in general from Poland (Another comma here.) let us know.
5. Who currently helps you?/Who is currently helping you? The second is more natural. 
6. Are your parents with yourself/you? 
7. Do you have money for living expenses?
8. I hope we'll be in contact. I hope to hear from you. 
9. We'll be glad if you respond./We'll be glad if you'll respond. I hope to hear from you covers this too. 

Are these sentences correct?

1. I'm the youngest brother of your husband./I'm your husband's youngest brother.
2. He told us that he'll take you and your children on vacation to Poland.
3. We were supposed to meet./We were supposed to know each other.
4. If you need anything from Polish department, or anything in general from Poland, let us know.
5. Who currently helps you?/Who is currently helping you?
6. Are your parents with you?
7. Do you have money for living?
8. I hope we'll be in contact.
9. We'll be glad if you respond./We'll be glad if you'll respond.