There were no Gilberts accused at Salem in 1692. However in 1654, Lydia Gilbert of Windsor, Connecticut was convicted of, and probably executed for, witchcraft. (The Salem Witchcraft Trials weren't an isolated incident; witch-hunting was not uncommon in colonial America, and Salem was the end of the American witch-trials, not the beginning as many people think.)
Lydia was probably the second wife of Thomas Gilbert Jr., son of Thomas Gilbert Sr. and Elizabeth Bennett of Wethersfield, Connecticut. There's a good discussion of the problems surrounding her identity in "The English Origin of Thomas Gilbert of Braintree Mass., and Wethersfield, Conn" by Douglas Richardson (in The American Genealogist 1992). She was accused of causing the death of Thomas' former employer, Henry Stiles, through witchcraft. While we don't have proof that Lydia was executed, it's extremely likely because Thomas remarried about a year after her conviction.
If you're interested or have a connection, I'd be happy to pass on other details about her and her family!