Hello Susan,
My name is Clare Horgan I am a volunteer for the Claregalway area in Co. Galway. I found what you found out, 6 silblings. Loughrea is lucky as St. Brendan's have records that go back that far. Few places have can go back that far.
I also found a widow Dillion in Moyleen townland, Loughrea Parish in 1828, which is just outside the town in the Tithes Applotments http://titheapplotmentbooks.nationalarchives.ie
In the Griffith Valuation: A Patrick Dillon is in Loughrea town: DUNKELLIN STREET (NORTH EAST END) in the 1850's. Patrick is a name of a son of theres but I can't collect? There was a Thomas too in Cabbage Lane but I can't find a sons name of Thomas for Cornelius and Catherine.
There are no Dillons in Moyleen in the Griffith's in the 1850's but there mare Quinns so it is possible they could be related through Catherine.
See the link below to townlands.ie, which is very helpful to find out information on all townlands in Ireland.
https://www.townlands.ie/galway/loughrea/loughrea/loughrea-rural/moylee…
If you wish to contact me for help and guidance, I would be only delighted to help.
My email is claregalway@irelandxo.com
Looking forward to hearing from you,
Clare