I find it helps to look at the most recent common ancestors MRCA, and use maiden names rather than married names for ladies.
MRCA of all four of you are parents of Jane and Sarah Williams, eg 'Fred' Williams and 'Jane Evans'. The Griffiths family doesn't come into the equation at all, you will get no shared matches on this line at all.
'Fred' Williams and 'Jane Evans' were your 2G grandparents, 2 of your matches 3G grandparents, undisclosed relationship to your 4th enigma match - 2G like yourself, 3G like the other two matches, or perhaps something else entirely?
That is 3rd cousin, 4th cousin once removed to you, or something else.
Look at DNA painter tool -
https://dnapainter.com/tools/sharedcmv4At this level you could expect to share
3rd cousin, avg 74 cMs, range 0 – 217 cMs
4th cousin once removed, avg 28 cMs, range 0 - 117 cMs
What you need to look at is matches with either Williams or 'Evans', bearing in mind that it depends entirely on who has tested what results you get. I have had very few matches with my maiden name.
Regards Margaret
