Checked the tree on F/S. In addition to John 1774 it lists Elizabeth 1777, Mary 1778, Anne 1781 and Joseph 1783.
From the Mancetter baptisms on FindMyPast (begin Feb 1776) I can confirm Elizabeth 13 Sep 1777, Mary 25 Oct 1778 and Joseph 10 Aug 1783. The images are available for Elizabeth and Joseph - Mary's is hidden under a note added to the sheet - but the record has been transcribed.
i cannot see a baptism for Anne on the Jan 1781 page.
In addition there's a baptism FindMyPast (image/transcription) of -
Samuel Windridge, 25 Dec 1784, Mancetter, parents John and Fanny