I think Eleanor and Elizabeth Hoskins who share Richard's grave are sisters not mother and daughter, judging by the 1851 census and ages at death. Their brother is the Rev James Hoskins, resident in Marchwise, Denbighshire in 1858
Not that this helps with finding out what has happened to Susannah -
for info. You would need to verify public tree on Anc*y has following details
Eleanor HOSKINSBorn 12 Nov 1775 Bridekirk, Cumberland
Died 19 Oct 1858 Registered: Great Boughton, Chester
Elizabeth HOSKINSBorn 20 Feb 1789 St Bridget, Beckermet, Cumberland
Died 19 Aug 1857 Registered: Great Boughton, Cheshire
Parents
Joseph HOSKINS b1751-1826 &
Eleanor SENHOUSE 1754-1823
1858 Probate for Eleanor 3 Nov granted to the
Rev John HOSKINS of Marchwise,
brother