Thanks, Kim.
Those three are listed as the children of James Aitken or Aikine, not James Aitkenhead. The jury is stilll out as to whether this James is an Aitkenhead who has shortened his surname, or someone totally unrelated.
However Janet born 26 December 1744 and baptised on 6 January 1745 (not 1744; the index is wrong) is described as daughter of James Aitken in Cadgerloan, and there is no record of any Aitkenheads being in Cadgerloan.
Also James Aitkenhead and Ann Fleming's eldest child seems likely to be Alexander, baptised 19 May 1744, and Janet Aitken was born only 7 months after Alexander was baptised. Also Alexander and his next two brothers were born in Blantyre, and they overlap with the three Aitken children born in EK, so it looks as if they are not all the same family.