Should I ask my boss to take my break?

We have two receptionists, one is on leave and the other is leaving this Friday.

I have to cover the reception desk from 8:30 till 5pm.

The girl that is leaving keeps telling me not to take my 10 min break in morning and afternoon so the other staff don't have to sit out there.

I am also doing a lunch setup for 8 lawyers and collect their food and stack away the groceries, deliver milk and fruit between two levels.

Would you ask your boss to take your breaks? I can have my 1 hr lunch break.

The girl that's leaving is like "forget about getting your coffee, it's only for one day, I never take my break."

That's cause she usually has the other receptionist there when she needs too.

I'm doing them a massive favour covering for them, she shouldn't be telling me not to take my breaks.

Updates
8 mo
I'm covering the Monday after she leaves on my own. No other receptionists will be there thar day.
Should I ask my boss to take my break?
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