As I've not been able to view the actual parish register, there could well be gaps in my information. So I wouldn't rule out Sarah being a daughter of Timothy & Elizabeth just yet.
My Timothy (son of Timothy & Elizabeth) named a daughter Sarah & Timothy snr's father also named a daughter Sarah, so the name seems to run in the family (I know it's not unusual
)
Do let me know how you get on & I'll try and do some more digging around. It's a shame that the images of these parish registers are not available on the familysearch site. As I've been able to sort out a lot of my other lines from other parishes.
Sue