What 80's Disney Tv Movie had a tarantula in it?

I remember seeing this movie on the Disney channel in the late 80's. So no, this was not "Home Alone" and this was not "Arcanaphobia." This family movie involved a young brother and sister, and the brother kept his pet tarantula in a shoebox, I think. One of their mother's friends (or boss?) came over to visit at the same time they found that the spider escaped! And then they saw that the spider was clinging to the visiting lady's back!!! If you can give me any clues as to what movie it was (I am pretty sure it was a tv-movie) I would greatly appreciate it. Thank you!