While only 5% of the pilots are women, flight attendants receive basic training for emergency situations, such as when the pilot is incapacitated. I wouldn't be surprised if a lot of them could actually land a plane in a life-and-death situation, or at least find a passenger who can.
With buses the picture is a bit brighter. If I had to guess, 20% of the bus drivers around the world are female? And a missing driver doesn't automatically spells your death - the bus might be going slow due to traffic, and a lot of people are able to at least step on a brake.
EDIT: I'm genuinely curious about the downvotes. If I said something that is either factually wrong (false) or morally wrong (sexist, insensitive, etc.), feel free to point out, as I can't guess anything based on downvotes alone.
Alternatively, if the downvotes are due to a faulty reasoning, then please show the flaw.
Also, if you have a driver's license, you probably know enough to safely stop a bus even if your license is for personal vehicles only. And while I don't know the numbers, I'm pretty sure the percentage is much higher.
Yup. The main concern in the bus situation is how suddenly the driver disappeared vs. reaction time of the passengers. If it's sudden enough, and the bus is fast enough, even if all passengers were able to drive it, odds are that it'll still crash.
Flight attendants won't be landing anything without flight controllers. Especially in busy airports like Heathrow. Even if you leave men pilots in place and only remove men traffic controllers, all the planes will crash.