Old Tintype

I found this photograph in some family things. All the photographs belonged to family members living in central Mississippi.

I believe it is a tintype as it is magnetic. It wasn't in any sleeve or frame and there is no writing or identification on it. It is bigger than your palm, say about hand-sized.

You may be able to see that they've added a little pink to her cheeks and a little gold to the pin on her collar. I'm not sure what that technique is called or when it was done exactly. I know I've seen the tinting done on more modern photographs, say from the 1930s-1940s.

If anybody is an expert on vintage fashion from the mid-late 1800s and may be able to date the clothing in the photograph, please share any information you may have.