The Fool (spoilers for all RotE books, including LST)

[Farseer]

Fitz had another matriarch experience separate from anyone else when he was recovering from something severe or was deeply lost in the Skill.

Yes, this was in the month that Fitz lost whilst heading from Aslevjal back to Buckkeep, just after he had accepted the kingly role from Kettricken and Chade. The immense presence made itself known to him in a star-like form (which I sat up and took note of given the connection to the Skill being a celestial magic, the presence of 'stars' in the Skill well etc! ).

Regardless of my insertions into the discussion re Fool and the jewelled Male, Female and Serpent facets of Sa, this experience was certainly only matriarchal for Fitz (just as the other experience on Others' Island had been matriarchal for him and patriarchal for Dutiful) as he noted her as a 'she'. That the presence asked Fitz, "You again?" suggests that she was possibly the same presence that he had touched before on Others' Island. Of course, that presence did speak of 'others', so she was only one of a large group of 'stars' (though from memory she was a brighter one than those she was surrounded by), and so it is also possible that he had touched another presence previously but this one had been aware it. I'm for the former though, and so believe it was the same presence.

It is interesting to note that Fitz himself felt that these contacts he had were with Elderlings, and so they were much more immense beings for him than the Elderlings that Fool spoke to him of (from memory, they discussed this while both were in Aslevjal and Fool was giving the Elderling/Abomination illustration to Fitz about the red roses with the white etc).

Nothing to do with anything really but it was also this event that caused at least one older woman to comment on Fitz, during his recovery back in Bucckeep, as having a "Pecksie-nibbled" look and this, for me, provided another connection between the Skill and Pecksies and the well of Skill silver/the Skill River (EDIT: not to mention Fool). Can't say much more for fear of Pecksie spoilers.