There is some information about her and her family in a couple of sources I have found.
The History of Parliament site has an article about her husband h
There is some information about the family in the Victoria History of Rutland, volume 2 see this link
and finally in the Visitation of Rutland there is the Sheffield family on page 19, and the St Lis or St Lise family on page 42
So she definitely seems to be the daughter of Roland or Rowland St Liz (or St Lis) and I think I would go with St Liz as her LNAB rather than Senlis. The Wikitree naming policy is to go with the name most recognised when there are variations in the sources.
By the way no source seems to name a daughter Lucy or a son Robert, and Robert's wife, Isabella STElizabeth, seems to be just another variation for his mother, which would make 3 profiles for her.
I also think her birth date of about 1355 is impossibly early, given she was perhaps married in the early 1400s.