Hi,
I looked at the Filey PRs at the East Yorkshire Records office today.
I found Althea's baptism okay -
Feb 23 1811 Althea d/o John & Elizabeth Fokinther
I'd almost given up on Joseph but I did another sweep just looking for the baptisms of any Josephs at that time, and came up with what I think must be him -
May 24 1810 Joseph s/o John & Elizabeth Fokey
I checked 1800-17 but couldn't find any other likely siblings.
Heaven knows what the correct version of the surname is supposed to be!!
Hope this helps,
Jill