I haven't had any luck with the names for Isabel. However, I have found a Joseph Le Patourel who was living in Guernsey in the 1901 Census. The family are listed as John LP (head)(age 65)...dock worker, wife Elizabeth, (age 60)...charwoman, Selina Le Patourel (age 22)...charwoman and Leonora Le Patourel (age 20),...dressmaker. Joseph LP is grandson (age 7) and Emily granddaughter (age 2 months). The children are named as Le Patourel, and the daughters are both listed as single? Don't know if this helps. I might be barking up the wrong tree entirely of course.
Know what you mean about brick walls too.....I've come across a few since I started with this hobby!