In search of a missing burial

Hello, this is my first post on this website; I'm hoping someone collectively you might help me to solve a family history mystery.

My great-grandparents met, married and settled in Liverpool, they were Irish Catholics who had crossed the water in the 1880s.  When my grandad was born in 1898, he was the youngest of 9 children, and his parents were running a pub in Liverpool near the docks.

His father William McLoughlin was from Tyrone and his mum Susan Kate Osborne (or Susannah Catherine, or any combination of the four!) from Oughterard, Co.Galway.  Not all his siblings survived into adulthood and its one of his sisters who died in childhood that I'm trying to trace a burial for. 

She was Rachel McLoughlin born 17 April 1891 at 'The Lambeth Hotel', 109 Smith Street in Liverpool.  She died on 6 August 1900, Fuerty, Roscommon, aged 9 years. On her death certificate she is the daughter of William McLoughlin, Hotel Keeper, Liverpool, which is correct. The informant is Thomas Webb, Fuerty, and was present at the death. He was married to Rachel's aunt Ellen (Susan's sister).  

The family headstone at the Ford Cemetery in Liverpool states that Rachel was 'interred in Ireland'.  I can find no information anywhere to say whereabouts she is buried and I have no idea why she was in Ireland in 1900. At that time her surviving siblings were 2, 5, 7, 13, 14 and 15 years old.   I don't know if she lived there, or was visiting her aunt and uncle.

Thomas Webb was a police constable and all his children were born in Co.Roscommon during the years that Rachel was alive.  In the 1901 census his address is Lissaneaville, Fuerty, Co.Roscommon.  This really doesn't mean much to me and doesn't appear to be a specific place, at least not that I can find. 

Rachel had other uncles and aunties who lived in Oughterard Co.Galway sometimes more specifically Kilcummin, Oughterard. 

So my question is, where the heck could this little 9 year old be buried? Her aunt Ellen died in 1921 Ballyfarnon Co.Roscommon but I don't know where she is buried.  Thomas Webb then moved over to Liverpool and died there in 1931.  

Its bothered me for years that Rachel isn't buried with the rest of her siblings and parents, I'd love to know where she rests. 

Can anyone point me in the right direction please? 

Many thanks, sorry its a bit long and rambly.

Lucy