To address her age... In the 1870 & 1880 census, Margaret is said to be born in 1867. This might explain the age discrepancy. I think she lied about her age.
'''1870 Census''': "1870 United States Federal Census"<br/>Year: 1870; Census Place: Liberty, Washington, Ohio; Roll: M593_1278; Page: 221B<br/>{{Ancestry Sharing|3358171|7b22746f6b656e223a22416f32654571506d583279524f6644654b5a56662f42465933696d4f42592f79654a715a4c486e786a70673d222c22746f6b656e5f76657273696f6e223a225632227d}} - {{Ancestry Record|7163|37248755}} (accessed 27 April 2023)<br/>Margaret F Mossburg (3), At Home, in Liberty, Washington, Ohio. Born in Ohio.
'''1880 Census''': "1880 United States Federal Census"<br/>Year: 1880; Census Place: Mckim, Pleasants, West Virginia; Roll: 1411; Page: 127C; Enumeration District: 176<br/>{{Ancestry Sharing|3358184|7b22746f6b656e223a226c2b374443496258496f61657a2f62346a374435627257595854357168794236344d556a6c4d683471644d3d222c22746f6b656e5f76657273696f6e223a225632227d}} - {{Ancestry Record|6742|14941576}} (accessed 27 April 2023)<br/>M F Mossburgh (13), single daughter, At Home, in household of William Mossburgh (40) in Mckim, Pleasants, West Virginia, USA. Born in Ohio.