Rebshidduch, I vehemently disagree with Mammale’s saying to be pushy. It will totally annoy the shadchan and turn her off.
Before the invention of caller id, you could call people as often as you like. But nowadays, if you keep calling someone, it annoys them since they can see on the caller id that the same person keeps calling.
I would not call more than once a day. If you leave a message, wait two days before calling again.
I’m not sure that you should leave a message the first time you call. I would wait until the second time, although it’s not a big deal either way.
I agree with Mammele that if you are having trouble getting through, it makes sense to vary the time of day. However, I would probably start by calling between 9:00 and 10:00 pm, and then try calling in the morning (before approximately 1:00).