Making up time off for poorly kids

[potatoes]

I work 3.5 days per week and in the last 2 months have had 2.5 days off when my kids have been poorly. Company policy is that this is paid. My boss has said if it happens again she will expect me to make my hours up. I know she has a business to run but I already do at least 2 hours unpaid overtime per week (I voluntarily gave up half my lunch break per day because we are always busy over lunch).
Also her words were "I expect part-timers to cover hours they have missed" - is this fair if full-timers aren't expected to do the same?
Any advice on where I stand would be greatly appreciated.

does not sound fair. what does your contract say?

Nothing in my contract, the HR policy for the company is that time off for dependants is allowed and managers must keep accurate records. Although my manager said there was a limit of 5 days, when i checked the policy it said there was no limit.Wouldn't be so bad if others, including my manager herself, didn't have time off for poorly partners, parents etc regularly and as far as I know nothing has been said about making time up!
My manager isn't the most rational person on earth so I am worried that if I try and talk to her it will be held against me forever!

Difficult, there is no legal entitlement to paid time off to look after sick dependents although you do have a right to a "reasonable" amount of unpaid leave to look after dependents. Unfortunately what is agreed to be "reasonable" depends on the employer.
I guess it depends on the exact wording of your contract as to whether or not you can negoiate if you have to make the time up. Does it say "time off is allowed" or does it say "reasonable time off is allowed" if it is the former then you probably have a stronger case. It does seem unfair that FT employees aren't asked to do the same.

Sorry just seen there's nothing the contract, in that case double check the wording of the HR policy.

Does the HR policy say paid time off or unpaid time off?

As a part timer you can't be treated less favorably than a full timer so if your manager is directly saying part timers have to make up time and full timers get paid time off, that would be illegal.

HR policy is paid time off.

Ok well if that's the policy it must apply to part timers as well www.direct.gov.uk/en/Employment/Employees/Flexibleworking/DG_173304here