Can you help me date this dress?

My aunt just showed me this incredible picture of my Great-Great-Grandmother and her children. They were members of the black elite in New Orleans and had money and property long before the abolition of slavery. I'm guessing this tintype is from the 1890s? Maybe the 1900s? Can anyone help with dating the dress?

https://preview.redd.it/v09ycgvwo8dc1.png?width=2048&format=png&auto=webp&s=617736cc1e4977d699dc03d19ca26795933dee8d