Janette, At familysearch.org the name is indexed as Lawyer Borat. So I looked for a Lawyer born approx. 1851 in New York and found this.

1900 census for Manhattan, NY
Lawyer Borst-age 47, born July 1852
Annie Borst-age 40-born March 1860

If you go to fultonhistory.com (it's a NY historic newspaper site) you will find an obituary for a Mrs. Harriet D. Calvin in 1915-it states her siblings are Henry Kennedy, Matthew Kennedy, John Kennedy, James Kennedy, Thomas Kennedy, Mrs. L. J. Borst, Mrs. Erwin Hall, Mrs. James Smith and Miss Marcella Kennedy.

You can find most of the siblings marriage records at familysearch.org. The parents listed for them are John Kennedy and Harriet Diamond/Dimond/Dimon.

You can find Lawyer Borst in the 1880 census with his mother Mary Borst and his siblings Charles and Sarah. Lawyer is also in the 1855 census with Harmon and Maryann Borst and siblings George H. and Charles Borst.

Good luck in your search. Kathryn