Hello David;
Gen. Cota had a sister named "Ardell Cota". To my knowledge, "Ardell" is his only sister? She is also mentioned in his biography "Division Commander" by Robert A. Miller.
According to Fran Cota-Johnson, there is a common ancestor that comes up... "Daniel Cota", from about 1798, born in St. Albans VT.
Can you ask or find additional information from your family as to your Grandmother being "An Unknown/unrecorded Member" or blood/half cousin of this Cota family group?
Best Regards;
Al (Alfred "Ed Moch" Cota)