@SueT
Make sure to mark the eggs and remove any laid by the others. I appreciate that her eggs are bantam eggs and you have mostly large fowl so the other eggs should be notably different but it is very common for hens to lay their eggs in a broody's nest and either push her out to do so, or sometimes climb in on top of her. Eggs can get broken like this although bantam eggs are usually more robust, but when the chicks start to hatch, there is a risk that they will get crushed by other hens climbing into the nest to lay, so once it gets close to hatch day, make some provision to seal off the nest area from the others to prevent such a tragedy.
Generally a broody will get off the nest herself once a day to eat drink and poop..... you will probably know when she has been out because there will be a huge stinking dollop of broody poop in the run to show for it. There is no real harm in getting her off the nest yourself once a day. If she has already been off, she will probably get straight back on so don't worry too much about it.
What you do need to be aware of is the risk of an infestation of red mites. Broody hens are a magnate for them like a 24/7 banqueting opportunity, so make sure she has access to a nice dry dust bathing area and check the nest.... You will see mites crawling on the eggs if they become a serious problem and your broody will be actively dust bathing every day. I always dust my broody nests with DE before I set eggs and again 2 or 3 times through the incubation period, just to keep the mites from getting out of control. I once had a trusted broody abandon her nest and eggs close to hatch date because it was alive with mites. I've been very proactive as regards broody nests since then.
Good luck with your hatch and I hope you get more pullets than cockerels. For your information, you can set eggs that are up to 2 weeks old, they don't have to be laid fresh that day, so if you wanted to add a couple more and it's only a day since you set them, you could sneak them under her. Once it gets past a day, you are into the complication of a staggered hatch.
Broody hens and chicks are the best type of chicken TV, so I hope you get the chance to observe them.
Best wishes
Barbara