These Larkin ancestors were likely married in Ireland around 1838 +/- 4 yrs. They likely had children in Ireland. The Famine started in 1845 and lasted thru the early 1850s. Many Irish migrated to England to escape.
Do you have a maiden namefor Margaret? Do you have placenames associated with their life in Ireland?
For Patrick Larkin (+variants), there are 427 B rcds and 171 M rcds associated with this name. Since their B dates are so early, it is unlikely the events were rcd'd. However, the marriage rcds MAY have been as would the B events for their children; these are at the ragged edge of geneological rcds for Ireland.