Hello Bev.
At first I thought I wasn't going to be able to help, but I might have some clues. I live in New Mexico, USA, but have ordered 2 films from the LDS Family History Library so often, they are on permanent loan to this local church, and I can access them at will. Film #1279216 and #1279217 have the Parochial Registers of the Catholic parish of Loughrea from 1810 to 1901, baptisms, marriages, deaths. Mind you, some years are missing in the film (maybe the original register pages were un-filmable?)
I went to the local library last night, and looked in 1825 for Maria, but did not see her baptism. When I came home I was thinking she might be in one of the other nearby local church records. I also thought the family might not have been Catholic, in which case these films won't help at all. The films have records from several churches in the Clonfert Diocese.
This morning, I found your tree online at Ancestry.com, and noticed (SPENCER tree) that you've got an 1861 England census attached to her. The census shows she was born about 1830 in Loughrea, so I will go back on Tuesday night (I work during the day) and look again in 1829 to 1831 time frame. (I'm trying to start with a "known", and go backwards in time as clues pop up).
Then, just now, I looked at the LDS website "FamilySearch.org" and found her marriage record! NOT in 1852 Limerick, but on the 1st of November 1851, IN LOUGHREA! The record can be ordered by you, thru any LDS church, if they have a Family History Library. Call around, or go to the website www.familysearch.org; click on the tab "Library" at the top left; select "Family History Centers" and then fill in the blanks on your location, and it will show you nearby centers. Film #101328. This film has a note "General Register Office", and it's called "Marriage records 1845-1870, with indexes to marriages 1845-1921." If the Hardy family was not Catholic, then they probably were Church of Ireland, in which case a whole other research route needs to be taken, and we might need the help of the Parish Admin. on this website.
Last night I checked on "AskaboutIreland.ie", (in the lower right select "Griffith's Valuation"), and I looked for "Hardy" in "Galway" in parish of "Loughrea" and found there were a few Hardy names. An Anne Hardy lived on Mob Hill, where it intersects with Castle St., and she sub-let her home to a few other families in 1856.
I looked in the Abbey Graveyard Internment Register, and did not see any Hardy or O'Hara names. But... that doesn't mean they are not there. This register was bound in 1895 for the Carmelite Fathers, and many names were transcribed from an older book, about 1900 or so. There is a note inside the front cover that says not to take the book outside, as weather can affect the writing. I figured that the first register was water damaged, and many names could not be read, so when the 2nd book arrived, they transcribed as many as they could read at the time. So, burial information might not be found, but Church records CAN be found! Whether or not they're Catholic or not, there's Church records... we've got to figure out which faith, then go from there.
The other old cemetery in Loughrea, GarryBreeda, has no register, but is also VERY OLD, and they could be there. There is also a graveyard at the old Church of Ireland/Protistant parish, which has now become the local library. I have no idea who we could contact to see if there is an internment register for that graveyard.
The other thing I noticed on your Ancestry trees is that Henry doesn't show siblings (HARDY family tree). I found that to enter just direct lineage on your tree hampers the clues to finding family. What I mean is that if you tract Henry's siblings, you might find their mom or dad living with them, for example in the 1851 or 1861 England censuses. If you load everyone you know about in the families, then tract them all through time with the census records, you might find clues as to where "grandma" was living or where "grandpa" was buried. After hunting for my g gr grandma (for 7 years!) I finally found her living with her grandson in Wisconsin after her own son moved to Oregon. She had lived with her son for MANY years, but I lost track of her when the son moved away. I never could find her death record until I found her with the grandson in another state! So, it would help to find more of Maria's siblings in the English censuses (if possible) and see if any others show Loughrea, and/or if Henry and Frank have and English records you can find online at Ancestry. You didn't post locations to the birth/deaths to some of Maria's siblings (HARDY family tree) and I'd bet a ton of record hints will show if you list locations, even if it said "Ireland" and/or "England" and/or "Australia".
Please email me MNAJPA@aol.com and I can provide further help if needed.
Mary Van Dyke