Of course much of what is at scotlandspeople is also at familysearch. It has the four Helen Lockhart baptisms.
1. b 1815, Dumbarton, parents John Lockhart, Janet McFarlane
2. b. 1813, Dundonald, parents John Lockhart, Janet Walker
(so if she had kids John and Janet, that won't help!)
3. Helen Sibbald Lockhart, b. 1812, Haddington, parents John Lockhart, Isabella McWilliam
4. b. 1812, Kettle, parents John Lockhart, Margaret Rollo
The original records at SP could also give information about their marriage (I'm not sure about early parish records before registration).
John Lockhart and Janet McFarlane married 1814, Dumbarton, but there are no details (e.g. fathers' names) at familysearch.
If she was accurate when she said 1816 as her dob (it's always possible!), #1 would be the most likely (Aug 1815 = census dob of 1816).
That couple also had children
Charles McGlashan Lockhart, 1816, Dumbarton
Duncan Lockhart, 1818, Dumbarton
and you can sarch at familysearch for children with the other parents in that time and place.
Not saying these are your people, just that these baptisms could be a fruitful path to wander down!
For good measure, there is James Clezie, b. 1816, Edrom, Berwick, parents George Clezie, Jean Lockie. Also:
Isabella Clezie, 1829, Edinburgh
George Clezie, 1825, Edinburgh
Janet Cleazie, 1825, Edinburgh (twins)
Agnes Clezie, 1814, Edrom