Thank you all, I think we'll order the M2 later today, it will do what we need it to do, ideally it would be a wearable one so monitors 24/7 but I know she wouldn't wear one of those, if only for 7 days a month.
Its not wearable 24/7. Its a chunky piece of kit. I cant imagine your missus will like carrying it on her person for all that time and certainly not in bed at night.
I'm not sure you need one for 24/7 anyhoo.
2 or 3 times day would be suffice and give you a good idea of BP