Wait for landlady to sell to me or buy now and move.

[Toddlerteaplease]

I am looking to buy. I live in a lovely but tiny house, in a very convenient location for me. (15 min walk to work)
My landlady is willing to sell but not for several years as she's tied into her mortgage. The rent is well below market rent so not a problem to stay. The house would probably be to end of budget, but needs nothing doing, and I've lived in it for 10 years. However I'm not sure I want to spent my absolute limit on a tiny house. It's would be an excellent investment due to the location.

Or do I look for something slightly larger/ cheaper and move now. I have no spare money for any work that needs doing, so would need to move into something 'perfect'
I really don't know what the best thing to do is. I've been waiting for 6 weeks to look at a house that ticks all my boxes and will make an offer if it's right. But if that's not an option I don't know what to do.

keep looking. If you find something you like that you can afford, take it.

Thanks, I asked if she could do some redecoration, which she has agreed too. But doesn't want to do if I'm going to move out in. I don't want to mess her around and promise I'm staying out if I'm not going to.

PigletJohn put it perfectly.
You don’t know for sure that she would sell, when it would be and would you be ok with the price. I would start looking around, it will take more time than you’re expecting.

If your head says move and your heart says stay - is there an option to get a sensible buy-to-let* and keep renting your current place below market value? Then when your landlady wants to sell you will know if it's right for you, and hopefully could then sell your buy to let place to facilitate that.

*I know nothing about this by the way only that it's not so simple, but on paper seems like a way to solve your problem.