Names, dates and places are necessary to locate the information and to prove that the George Kerr you locate is the same person as the George Kerr who is your ancestor.
Also remember everything is not on the internet and there may be mistakes on what is found on the internet.
The family history website at www.familysearch.org
has the largest collection of information. The website is free to use - they have a project where volunteers transcribe the records - some records are restricted to the volunteers.
You posted this message in the board about Ships from Ireland - you will discover that there are thousands of Kerr's and McGrath's in Ireland.
Although your message, does not say so, I'm guessing you already have the 1910 and 1930 US census info for George and Pauline. They lived in Brooklyn. 1910 is where you find Margaret McGrath age 75 yrs
1930 census says George born 1865, immigrated 1876 also in the home are Edith Reysdick, Irene Reysdick, John Brocker, Edmond Rysdick - any idea who these people are ?
I'm guessing you want to find particulars about where in Ireland - in which case you will need to focus on George and Pauline - their marriage record, death certificates, death notices in the newspapers, birth records of the children, baptism records may list godparents who may be the aunts and uncles - learn the names of their brothers and sisters.
Hopefully you live near Brooklyn and can go to the public records office to research in the public records for births, marriages and deaths. Also go to the library and research in the Brooklyn newspapers for death notices.
There is an 1870 census with George Kerr age 4 - 21st ward Brooklyn
Try to provide specific details in your messages and focus each message on a particular time and place. Tell what you have already found so people do not spend their efforts telling you what you already know - rather that they would spend their time searching for what specifically is missing.
For example a message about cemetery records for the Kerr's may lead to specific dates of death which are very helpful to research in the newspapers. But if you already have the dates of deaths - then say so and then people
Good luck and I hope you enjoy the research.