Black Belts are not required to wear head gear or chest protectors. This is good reason to wear protection even at higher ranks because even a Green belt can slip one in on you.
You cannot be worried about getting thrown. Reese was too tentative and got thrown easily. You must be aggressive with your combinations to keep the adversary at bay.
In this fight the focus by the brown belt was on the takedown and less on setting up the throw with punching and kicking. The green belt should have moved more and countered the takedown with range-one techniques.
Brother is working with little sister.
The purple belt is getting better, but he needs to move more and work combinations.
When a smaller fighter is sparring a larger fighter he/she must move. If the larger opponent get their hands on the smaller fighter they can control the outcome of the fight, so you must move in and out and sideways while striking. The purple belt has been sparring for a while and it shows, but the green belt is getting better each time she fights.