The singer-songwriter said, 'Yes' while on vacation in Mexico

Kara DioGuardi has to deal with a couple of big changes in her life ... both of them good.

Besides debuting as "American Idol's" fourth judge Tuesday, Jan. 13, the singer-songwriter also announced that she recently got engaged in December, reports People.

DioGuardi, 38, and her beau Mike McCuddy, 34, became engaged Dec. 8 while vacationing in Mexico.

Thus far, no wedding date has been planned.

McCuddy is a general contractor who is also already a father.

DioGuardi's presence at the "Idol" judging table has received mixed reviews so far. Although she has the background -- having written and produced numerous international pop hits and even guiding former "Idol" contestants -- her dynamic with the other judges, especially Simon Cowell, has yet to be fully established.