Is there just one woman who does most voiceovers for female-oriented commercials?

(This is a US-oriented question, but there might be an equivalent in other English-speaking countries.)

In recent months, I noticed that television commercials for products marketed primarily towards women – primarily food products, but also many other types of goods – are narrated by one person. It’s a woman who has a slightly lower-than-normal voice, who speaks in a slightly “ironic” inflection. Whoever it is, she’s pretty much the Don LaFontaine of commercials for scented candles, yogurt, and other products marketed towards middle-class “on the go” women. Is this really the case, where one woman has a lock on performing voiceovers for most than half of these commercials?

I hear Janet Ault’s voice quite a bit.

I’m not sure if it’s really her, I keep hearing somebody who sounds just like Christine Lahti doing ads for some kind of soap and/or beauty product and also for some kind of car.

I seem to hear Sally Kellerman’s voice in a lot of ads.