The person doing care work may need practical relief before they can explain how tired they are.

Tiredness past a certain depth stops being describable. Somebody in the middle of daily care often cannot answer what they need, because answering means standing outside the work long enough to see it, and no such gap exists in the day. An open question can land as one more task. Relief usually has to come first, and any explanation arrives afterwards, if it arrives at all.

Rather than asking what would help, offer something specific and easy to accept. Two hours on Saturday, a meal left on the step, a lift to an appointment. Give it without needing gratitude or a full account of how bad things are.