I think it's hard for us who aren't seeing the inside of a covid-19 ward to truly understand.
As I understand it, OP works in nursing and has full PPE but has recently been exposed to covid-19 and has remained at work although not going home. To me, a member of the general public, it sounds like she shouldn't even be at work but isolating for 7 days. Although I understand I may have interpreted OP's words wrongly. If this is the case then she should be off sick and paid sick leave.
Everything else about her husband and daughter would be irrelevant if this were the case as her DH would be able to take 14 days leave from his job in order to care for his child while his wife isolates.
Alternatively I instead assume that recently OP has removed herself from the family home as her work with covid-19 patients is raising anxiety and stress levels in the home. Which leaves her in the predicament of not having night time childcare for her daughter and therefore her husband, on a zero hours contract, has said he is not available to work at this time.
OP's situation now is that this is directly impacting on her finances as they have dropped to a single income household.
OP has two choices and neither are palatable. The easy but financially impractical choice is to relocate for the duration. The difficult choice is to remain home but isolate and socially distance within the home, sanitising etc on a regular basis in order to reduce the risk of transmission.
DH works with a colleague who has a high risk shielding partner. They have managed to stay in the family home by adhering to what some of us would see as excessive practices when it comes to returning home. as little as possible from work is brought home, and they don't work in a particularly high risk environment - certainly nothing like a covid ward. They shower and put fresh clothes on when leaving work, including shoes. Uniform is bagged before getting in the shower and bagged again with a clean bag after the shower, followed by sanitising hands again. Shoes are changed when finishing work and again when getting home - the home is effectively a clean environment. Nothing from outside the home is brought in before it has been cleaned - grocery shopping etc gets wiped over thoroughly before it enters the house. Wallets stay in the car and phones are sanitised before being brought in. I think they have even been known to bag the phone before going out and disposing of the 'soiled' bag on their return home and then sanitising their phone. They have a shower and clean clothes if they have to go shopping at all and limit their shopping to one shop on any given day.
The DH here is still able to go to work so is likely lower risk, although higher risk than non-asthmatic Joe Public. So I think OP has been a little unreasonable to expect a freebie pay packet because of the choice she has made to not be at home but continue working after contact with covid-19. If this were any other member of the public than a nurse, people would be baying for blood for someone who had been exposed yet knowingly continued to work.