Thanks. Here’s the result:
Spoiler!
The Celtic/Gaulish is interesting. The closest Germanic source, Alh10, seems to cause most of the distance for my mother. So I played around with other sources and ended up adding this one for her Germanic ancestry, which closed the distance by a lot:
Germanic_(NW255a):NW255a_Germany_Early_Medieval.SG _1476_ybp,52.54,25.61,7.98,6.28,0.00,5.74,0.00,0.0 0,0.07,0.00,0.37,0.00,1.41
Spoiler!
These two worked to bring out the Gaulish:
Gaulish_(NOR3-6): France_IA_NOR3-6,44.12,24.13,17.5,7.58,0.59,2.92,1.83,0,0,0.71,0. 38,0.24,0
Gaulish_(PEY53): France_IA_PEY53,53.92,15.17,13.26,6.82,6.26,2.42,0 ,0,0,0.82,1.32,0,0
Spoiler!
But I think this one is cleaner than the two Gaulish sources:
Proto-Celtic_(BIS130): France_BA_BIS130,45.67,18.46,17.38,13.12,0.15,0.1, 0,0.91,0,1.49,1.98,0.76,0
Spoiler!
I don’t really know what I’m doing, but the final result seems plausible and with a good distance. On MyHeritage, my mother’s Greek first cousin has a percentage of “North and West European” that more or less corresponds with the extra Celtic and Germanic (Venetian influence maybe). And I think the Levantine ancestry may come from the Mardaites, a military (not ethnic) group, like the French Foreign Legion, that recruited heavily in Lebanon before settling in Kefalonia and other parts of Greece.

