I found animated versions; it’s not them. The version I saw was not animated.
I found live action musical version, 1986; it’s not the one I saw. The version I saw was not a musical.
I found another live action version, 1991; but the frog is 3-5 times the size of the frog I saw.
I found the faerie tale theatre version, which I also saw in late 80s, early 90s; I enjoyed it as a child, but it’s not the version I’m looking for.
I’ll add details of the version I saw:
The frog in the version I saw reminds me of the frog in the film “Frog” starring Scott Grimes (Critters, Critters 2). It’s not huge, somewhat natural looking, and I think it may have been an actual live frog.
The young woman in the film reminds me of Robin Wright when she portrayed Princess Buttercup in The Princess Bride. I remember her washing utensils, which I thought was distinctive as films usually do not include details like this.
The prince has a beard, is fairly quiet, subtle, like he could disappear into a crowd if he wanted to.
This version might have been a for-TV-only version and limited to a region. I viewed it in Los Angeles, California in the late 80s, possibly the early 90s, definitively not after 1994.