Searching for Margaret Malone: Did she emigrate to the US to join her husband Robert Galvin and her sons?

There are certain ancestors that I feel a stronger inclination to find out more about. Margaret Malone, baptised in Ballyhea in 1858, is one of those, possibly because my grandmother has the same name. She married Robert Galvin in the chapel at Ballyhea on 29 April 1893, and the couple subsequently had four sons- John James (1896), Patrick (1897), Maurice (1899) and James Robert (1901)- all born in Ballinadrideen. 

In the 1901 census the parents and three older sons were all living in Ballinadrideen, but by the time of the 1911 census, only Margaret (listed as married and a farmer) and the two younger sons, Maurice (11) and James (9) were still living there.

Robert, it appears from various shipping lists, had been naturalised in the United States already- either prior to his marriage in 1893, or in 1895. Possibly he was living there already in 1911?

I have found the two older sons  on shipping lists.  Patrick Galvin(15) arrived in New York on 19 Sep 1913 (ship Cedir?) with his father Robert (50), and was on the list of United States Citizens- with naturalization details given for Robert. John Galvin (17) arrived by himself a year later in 1914 on the Baltic, on a list of aliens, as a student. His last permanent address was given as Ireland, Charleville. The complete address of the nearest relative or friend in the country from whence the alien came was given as his mother Margaret Galvin, Ballyhea, Charleville, Cork.

Next time I go to the library I want to check the immigration records for New York more thoroughly. Can I find the arrival of Maurice and James Robert? I know that both of these sons married in Manhattan in 1926 and 1934, so they must have emigrated before then. Both these sons were later buried in Calvary Cemetery, Woodside, Queens County, NY, along with father Robert and older brother John.

But what about Margaret? Did she ever emigrate? So far I haven't found her death in Ireland- though some people have a Margaret Galvin buried in Kanturk- but I am pretty sure that is the wife of farmer local to Kanturk. Could she have married again after Robert died in 1922 in NY?

Next steps to finding her will possibly lie in the emigration lists to New York. Could she have arrived there with either of her youngest sons? And I have noticed there is a 1925 New York State census. Could she be listed there with one of her sons? Time will tell if I find anything, but later today I intend to visit the local library so I can look at US records on Ancestry. 

UPDATE: I didn't find Margaret's emigration to the US yesterday, but I did find her two youngest sons, James and Maurice, who emigrated to New York in 1916. Interestingly, their nearest relative in Ireland was given then as their aunt, Mrs White, in Charleville, rather than their mother. They sailed from Liverpool. Both boys were listed on the aliens list, but their status was overwritten with USCit later. I have done another search for Margaret's death entry in Ireland but still not successful. 
I did see an entry for a Margaret Galvin who was detained in immigration as being insane, and was sent to hospital. I disregarded this entry, but actually I need to look at it more closely. That needs to be on my list next time I go to the library!