I am not a big fan of stand-up, and find most of the prominent female stand-up comics even more irritating then the men (Paula Poundstone, anyone). But back in the '90s on Comedy Central I remember seeing one lady who was pretty funny. Here is about all I remember: She was kind of thin and blonde and pixie-ish. I think her first name was Laurie or Lori, and her last name sounded Jewish. She had a real deadpan delivery and would sort of slip her punchlines under the radar. One I remember was “I saw a BMW with a bumper sticker that said ‘Just Do It.’ So I jammed the accelerator and ran into him.”
I agree with UC, but just in case that is not the one, two other Jewish female comics from that era are Cathy Ladman and Susie Essman- don’t recall how tall, but both have black hair.
I’m thinking Wendy Liebman, too. That delivery is hers, perfectly, and aside from the hair colour (like UC, I don’t think I’ve ever seen her not brunette), the physical description works for me.
It’s definitely, without a doubt Wendy Liebman. I really like her too. She only has that one schtick (the deadpan, afterthought, whispered punchlines), but she makes it work.
Based on the OP’s description of “slipping a punchline in under the radar” my guess is Rita Rudner. The first time I saw her, the joke that got me was “I was jealous because other girls had hickeys. So I gave myself a hickey. (laughter from audience ) And then people kept saying, ‘what is that on Rita’s forehead?’”
Edit: Ooops. I totally missed the OPs confirmation of someone else’s guess. Sorry!