My sister has a 95% ancestry dna match with a woman who posted Gedmatch results from the other two major companies. This woman did not post her ancestry results.

Autosomal results on gedmatch for my sister and her match are virtually identical. They share two regions on the same chromosome: a 10 cM segment with 2154 SNPs and a 13.9 segment with 3736/3681 SNPs.

The M account shows X DNA as follows:
Adjusted cM X DNA 13.5
Total cM X DNA 27 cM
Largest segment 7.1 with 653 SNPs.

The F account shows no X DNA.

I have two questions.

Why would X DNA show on the M account but not on the F? If M accounts do a better job reporting X DNA than F accounts do that may be a reason to prefer M tests for gedmatch posting.

Is the X DNA on the M account significant enough that I should restrict my research to my sister's X DNA family lines (even though no shared X DNA showed on the F account)?

Blanche