Frances Mary Broadwood UK? - Can you date this picture?

[Braindead]

This shows my great great grandmother, Frances Mary Broadwood. It is a glass positive picture in a leather frame. My grandma wrote a note on the back which says "Tatiana's "Russian lady" mother. Young Tania looks just like her." There is no studio identification on the picture or frame.
Some years ago, the RootsChat community were really helpful in assisting me to find out about my "Russian" great grandma - who was actually born in London, but I'm just curious as to what date people would put on this picture. Also, in your opinion, are the clothes British? After her marriage, Frances lived in the United States and Austria as well as the UK.
Thanks in advance.

[Treetotal]

I would say this is an 1860s ambrotype in a union case, it's slightly tinted and it is in lovely condition.
You are lucky to have it.
Carol

[Braindead]

Thank you for that information. It's a great help.

[Gadget]

A lovely image.

Did she marry Michel Bartholomai , Kensington, Q2, 1879?

Add - and died in Viena in 1884, leaving her English estate (£5500 + ) to husband Michel ??                             

[Braindead]

A lovely image.

Did she marry Michel Bartholomai , Kensington, Q2, 1879?

Add - and died in Viena in 1884, leaving her English estate (£5500 + ) to husband Michel ??                           

Yes, that's her. She seems to have been a very interesting character who seems to have undergone several changes of name in her life. Her husband was attached to the Russian Embassy in London and became Russian ambassador to the USA.