Mmm ... I got the feeling through researching the WHITE family, that maybe Agnes was "estranged" from her sisters ?? [None of her sister's children, are in included in the Will ? Also a brother-in-law, nephew Mr Reginald MICHAELS, appears to have been instrumental in challenging Agnes's Will. ]
I have info for the sisters, if you'd like it.
Is does certainly seem though that Agnes was especially fond of the FITZPATRICK children and their offspring ... so perhaps they became "her family" ?
~ Lu
Edit: Correction to above - re: name / relationship.