Parents of Mary Ann Taggart

My 2 x's great grandmother Mary Ann Taggart married Thomas Wright Vennard June 3 1846 in Tartaraghan Parish Church (FamilySearch.org name lists as Mary Anne Taggert to Thomas Venert    Indexing Project (Batch) Number  M70162-7  System Origin  Ireland-ODM  GS Film number  101278  Reference ID)., Mary Ann Taggart died June 4 1909 in Glasgow. Her death certificate of 1909 in Renfrew Glasgow lists parents as Frank (farmer) and Ann Taggart. I am having a hard time reading the maiden name of Ann but appears to be Baxter or Barber. I've been unable to confirm Mary Ann's birth information aside from would be approx 1824 & I am having difficulty finding any further information on her parents. Any help would be appreciated.I am wondering if possible her parents would be listed on the marriage document or if possible to find any further information about Mary Ann or her parents prior to her marriage. Mary Ann's husband Thomas Wright Vennard became a missionary for the United Presbyterian Church so I suspect Mary Ann's family would have similar religious affinity. It is believed Thomas Wright Vennard trained as a missionary between 1846 and 1853 before settling in Cathcart Glasgow. He was a missionary in NorthMavine Shetlands according to 1881 census. Any help would be appreciated in following Mary Ann's ancestry backwards through her parents or in fleshing out any details on Mary Ann Taggart and Thomas Wright Vennard. Thomas Wright Vennards parents as listed as William (sometimes Thomas) Vennard and Ann Wright. I have no details on them so if anything for them comes up, that too would be be wonderful.