Time poor - exercise bike? Any better ideas?

Not sure whether this is realistic because it’s quite expensive but a peloton and membership was a game changer for me for exactly the reasons that you describe.

You can get second hand ones more reasonably priced now but they literally have thousands of different classes and the community is lovely.

A real bike with a child seat on the back for nursery run?

Way more fun and saves time

You already do a lot of walking which is great. Instead of more cardio, could I suggest weightlifting and yoga or Pilates as a good next step for strength exercises instead?

A good set of weights are cheaper than most good exercise bikes, and there are loads of programmes on YouTube to follow.

I don’t find the static bike (turbo trainer in my case helpful). I have a similar BMI to you and so for me exercise is about mental well-being and distance from my other responsibilities. So I either go for walks (I have a dodgy Achilles that doesn’t like running), or pop to the gym or the pool (we have a gym close by). I also go out on my bike. For me it’s the actual act of making time for myself that’s important, so you could commit to an exercise class.

I have these activities ranked in order of time/prep, for me swimming is quickest, followed by a gym session (I’ll cycle up and be out of the house 45-60 minutes or a bit longer depending on what I do). A walk will take me a good 30-45 minutes, bike 30-120 minutes. So I tend to think about what time I have available and slot something in.

the videos on eg Apple fitness are good but again I get bothered by kids/husband and sometimes it adds to the stress.

What about exercise video on YouTube? Lots of variations. If you are familiar with a routine and you have a tablet or laptop you can prop it up next to the TV and watch TV at the same time.