What is the best business structure for laundry and ironing services?

My partner (we aren’t married) is currently registered as an auto entrepreneur for nettoyage services in France. She cleans a number of apartments in France during the summer and winter seasons and invoices the UK based owners. Currently the laundry is done by a 3rd party company that invoice directly with the owners. We are considering setting up a laundry/ironing business so that we can take on this work rather than it going to a 3rd party. If she chose to do this herself, without any involvement from me, is laundry/ironing already covered under nettoyage services and if not, can this activity be added for an auto-entrepreneur?

1. Assuming laundry/ironing is an activity that can be carried out under an auto-entrepreneur business regime; my understanding is that I couldn’t register myself as an auto-entrepreneur because we’d be at the same address and servicing the same clients. As were not married, I also can’t join her existing business via the conjoint collaborateur option. Can you confirm my understanding is correct on these points?
2. I’m also concerned that if she invoices both for cleaning and laundry/ironing, she’ll go above the auto-entrepreneur 32,600 euro annual limit. This would mean she’d need to setup a different business regime in France?
3. Do all other regimes mean registering and therefore charging clients TVA?
4. If the answer to the above is yes, this clearly adds 19.6% to our clients cleaning costs (I believe they already are charged TVA for their laundry). Other than her reducing her margin, is there any other way to limit the impact on the owners?