Hi Kylie
I can't see anything about Jonet HERIOT and James WATSON specifically but here are some mentions of a WATSON family in the vicinity which they're very likely to be part of.
(Edited from “Gorgie and Dalry” by Malcolm Cant):
“The lands of Saughton were held by the Abbey of Holyroodhouse until the end of the 16thC. Thereafter divided between various proprietors up to the mid 17thC, well known family names appearing in the records include WATSON, MORISON and DALZELL. William WATSON and his descendants were a family frequently involved in disputes and litigation. William in trouble with the authorities for being absent from army musters of 1544 and 1546. In 1569 his son James fell out with the THOMSON family over failure to pay a loan and same year lost an action against Johnne STANEHOPE, the miller at Stenhouse, for the supply of oatmeal. A few months later James won a case against the THOMSONs who were found guilty of carrying off WATSON’s livestock “under silence of nyght”. In 1590, the third generation, John, following a land transaction with John COUTTS of Dalry, was severely reprimanded by the Kirk Session of St Cuthbert’s.
Between 1600 and 1650 the lands of Saughton had various owners, MORISON family took over from John WATSON and John DALZELL. MORISONs then sold the lands to Thomas MOODIE of Dalry in 1639. In 1660 Moodie’s daughter sold Saughton to Robert BAIRD, merchant and baillie in Edinburgh”.
Probably not much help, but it gives a flavour of the times!
Anne