Great news---according to the probate record for Roswell Place, died at St. George, VT, 1872, Senara/Cinara Burt was listed in his will as his sister, which would make her daughter of Robert Place and Lucy Lincoln.

There is some other family information that I think would be very interesting to you in Roswell's will.

These probate records are free on the LDS (pilot) site:

http://pilot.familysearch.org/recordsearch/start.html#p=home

You have to click on Browse collections, then click on the correct place on the map, then scroll down the page until you get to the listings of databases and look for Vermont Probate files, then search for the person you are looking for.

Good luck, and hope this was helpful to you.