Hi Dalkey MC
I was out in Dun Laoghaire Library yesterday and went back as far as the 1911 Thom’s Directory but could find no mention of Tyrrell’s Lane nor could I find anyone named Tyrrell listed. I had this problem when trying to find Valetta Avenue, the address my G/Grandfather was living at in ’01 and ’11. Assuming now that the name predated both census and was no longer in use (from 1911 anyway) I had a look again at the Census and found there were four dwellings listed in 1911 on Tyrrell’s Lane but seven in 1901 so I have had a look at the Griffiths Valuation on the askaboutireland site and there is a Gerald Tyrrell listed both as a renter of land and landlord with property all over Dalkey. Five of his sites on the Griffiths Valuation Map might fit the bill; they are numbers 21, 23, 24, 25 and 36. The latter had the magical seven dwellings but it is far removed from where both you and I had thought the Lane might have been.
Anyway, have a look, it might help to narrow down your search and I will keep looking.
I wish your husband well.
John.