Refused Jobseekers Benefit due to casual work

Hi, hoping someone can shed some light on this situation as it seems wrong to me.

My sister was working full time since 2012 but has recently become unemployed. An old colleague of hers has offered her some casual freelance work, but this will only be a few days a month and nothing is guaranteed. She did a few hours work for him last week.

Today my sister had her interview with social welfare for the jobseekers benefit (which she should be entitled to based on her PRSI contributions). She was told that due to the occasional freelance work she is now self employed and cannot claim jobseekers benefit. They also said self employed people can apply for jobseekers allowance, but she won't qualify for it due to her partner's earnings, which are nothing substantial but too high according to the welfare.

She's extremely upset about the situation as she doesn't want to be solely reliant on her partner, who cannot afford to support both of them for very long what with high rents and other expenses he has. It seems crazy to me that some minor casual work (which has potential to turn into something more substantial in a few months) has lost her any entitlements.

Is this really correct? I just can't understand the rationale behind this. Would they prefer she didn't bother doing any work at all because that's what it sounds like?

Thanks in advance to anyone who can provide some insight.