I am looking for information on parents and/or siblings of my GGGGgrandmother, Anna Margaret Hartman, born about 1753. Collaterally, I'm looking for birth records of her children.

According to NSDAR, Margaret married my GGGGgrandfather Christian Gilbert in 1775. I can place Christian in Germantown, Philadelphia in March 1775; Bedminster Twp, Bucks county PA in 1779 through 1781; Franklin county PA in 1790; Frederick county MD in 1800; and Washington county MD in 1809 through his death in 1812.

Christian's will lists the following children:
Mary, wife of John Moggins
Jacob
Catherine, wife of Abraham Mayers
Saul
Elizabeth, wife of Charles Cline
Eve, (wife of Frederick Dietrick from a different source)
Mary
Christina
John (my GGGgrandfather b. 1791 d.1861)
David

I've just started researching my family, but I'll share whatever I have. Thanks, DON