Help dating 3 tintypes taken in Rochester, NY

[tcoyle20]

I received a big old box of unmarked photos and these three tintypes appear to be taken around the same time, but I don't really know when. I do know that there were two sets of immigrants that came to Rochester, NY in my family. Coyle and Hayes families from Ireland and the Link family from Germany came around 1850. Krenzer and Kesel families came around 1880 from Germany. I cannot tell which family these tintypes may be attributed to, my guess is that they are the Irish family/ies and the date is closer to 1870, but it would be great to have more than my guess to work from. I would be grateful for any guidance.

[Treetotal]

Hi and welcome to RootsChat, I'm thinking that the first one could be 1870s and the other two 1880s.
Carol

[tcoyle20]

Hi Carol, and thanks for looking at these photos. In the first photo from the 1870s, is the girl or boy older? Is the girl potentially one year older?

[Treetotal]

It's possible...she looks smaller than the boy but appears more mature.
Carol

[Erato]

I think the boy looks older.

[IgorStrav]

Me too, Erato - but they are definitely very close in age.

[Erato]

Maybe they're twins. 

[Treetotal]

Maybe they're twins.

I considered  that too, you always get one smaller than the other.

Carol

[Erato]

My mother had a twin brother and there was a set of boy/girl twins in my grandfather's family, too.  In both cases, the parents dressed them in sort of matching outfits.  But maybe not all parents tried to dress twins the same.