I am trying to find a person I only know her maiden name margrete sweeny and lived glasgow

Maybe you could try the Electoral register, it may only give an address for her maiden name, but her parents may still live there,so you might be able to find out what happened to her from them.

A registry office will have dates of birth, addresses, marriages etc.

There is probably a procedure to go through as personal information is not usually given freely, but they may be able to point you in the general direction.

Alternatively you might think about putting an add the local paper,perhaps in the local area to where she once lived.

Do you know her approximate age or possibly the name of her father or mother? Also, do you know how long ago she resided in Glasgow?