There's no law which requires an employer to grant Compassionate Leave. There's actually no law which requires an employer to grant Annual Leave, either, AFAIK!
When my mum died last year my company gave me 5 days off without any discount from my annual leave. Hence now I don't mind if they need a favour from me.
Generally people will get the day off, there are some who are so so unlucky and have had 3 Aunties, 2 Cousins and 5 Nans die in a year, they take it as A/L