The plot thickens

There are other things going on, like Mum breaking her leg and Toby spiking a temperature of 40.2 and Ocado forgetting to bring me onions. But I can't stop thinking about the fact that someone who stayed in this house over Christmas is pregnant. More than that, they're pregnant and haven't told me.
I've tried to work it out a la Sherlock Holmes, but I can't get any further than that the person is question is A) female and B) someone I know, which isn't very helpful. If pregnancy tests gave any useful information, like whether the baby's going to be tall, or have red hair, or is wanted or unwanted, I'd have more clues to go on.
I have a very strict code of conduct about such things. If someone hasn't told me something, it means they don't want me to know it, and so I don't pry. When presented with some item of gossip, I smile sweetly and say, 'That's not something I know anything about.'
I'm not wildly popular at the school gate.
The thing is that there's some satisfaction in smiling sweetly and declining to participate in salacious gossip. And I usually get to hear it anyway, so I get the gossip without the guilt. But believe you me, there is no satisfaction whatsoever in knowing something so incredibly significant and being utterly unable to share it with anyone.
And if the person in question is indeed female and known to me, why haven't they told me?
I'm going to drive myself mad.
Correction. I'm going to drive myself madder.
Think, Clementine, think. Where's Doctor Watson when you need him?