You might consider our family spelling or Flindle.
You indicated you have Joanna's will that mentions her brothers. Would one of them be a Thomas Flindell married to a Mary ??
Our family tree starts at Thomas and Mary in Northaw, England with two sons Thomas (1734) and James (1739). We have nothing for THomas or Mary and have searched church records in Hertfordshire in vain.
We have all of canada sewed up starting with John Morris Flindall (b.6 Mar 1775) arriving in Canada abt 1813. let me know if this is useful.