I think the fact that you are a woman is an asset when canvassing. That you are canvassing bungalows negates that asset though.
Unless you can do low level ladder work i think realistically you will struggle for ages to build up any meaningful income.
You might be lucky and hit a hot spot, but the market you are targetting is only a small percentage of work out there. Then take into account a good success rate might be 5% anyway and you have some idea of scale of your task.
Without being able to do at least an upstairs terrace, your only real option is being employed by a traditional cleaner, doing the downstairs while they do the tops. ie your boyfriend.
Other ground floor stuff like shop windows, is pretty much sewn up.
Or even better advertise yourself as an internal window cleaner.
Parish magazines and shop windows would be good places for you to advertise. Make sure you give a landline number and leave the advert reader in no doubt you are a woman.
I think you could build up a good round over time if you concentrated on internal windows. Most wc (i'm guessing are like me) don't like doing insides cos of the faffing about and the reactions to pricing accordingly.
And the fact of having a female inside someones house is non-threatening to most people.
Without a ladder i can't think of a healthier market for you.
Good luck to you for what you are trying to do. I think you are bound to succeed, if you have got this far with the idea.
If you target and pick up internal window cleaning work, don't forget to come back and post about it. Cos there will be other things you will need to take into account. Primarily your safety. Etc.