Margaret Harrison - born in Ireland, Co. Roscommon abt. July 1862

I found this marriage record on the Family Search website and ordered the microfilm and found the following information for my great grandmother.

Date of Marriage: August 6th 1878 - Saint Peter Church, Jersey City, Hudson, New Jersey, USA
Groom: John Maher (21) (gardener) born & living in Jersey City of Patrick Maher & Jane Earle
Bride: Maggie Harrison 17, born in Ireland Co Roscommon and living in Jersey City of Patrick Harrison and Bridget Lemmon

I am interested in any additional information about her and her parents in Ireland. (This is all I have to go on at this point.)

Any help would be appreciated,
Thanks, Brian