PAYE employee + very small once off additional income

Hi all , hoping someone can help me. Currently I am working in a job where I earn about 26000 euro a year . In addition to this, this July I worked with a family who was in receipt of a grant for their autistic child. It clearly states in the claim form for this garnt that it is the parents responsibility to make the necessary tax and PRSI deductions on behalf of the tutor. However I found out a few weeks into this job that the parents were not doing this. The parents then contacted the revenue and did not tell the whole story. Basically Ive been now told that it is up to me to declare it.It is only a very small sum of 500 euro but as the revenue have told me that I need to declare it I am wondering if their is any possible way that I can do this with out claiming to be self employed as I would be afraid that if I did this and was left unemployed in the future I could not seek unemployment benefit... Please help!! I dont have a clue how to go about this......
Thanks

I would be inclined to give back the €500, and pretend it never happened.

If I was in your situation (PAYE worker), I don't think it would be worth the hassle from the revenue or having to hire accountants etc.

You are entitled to JobSeekers benefit on the basis of your PAYE PRSI "A" rate. The issue at hand is that the employer in this case the parents of the child should be declaring you are the "A" rate also. They get a deduction for the amount and you have income at that amount. I don't know where the issue of you having to be self-employed came from. The employment of a carer for a disabled person is to be handled under normal PAYE rules, not self-employment. However even if self-employment is the route you have to follow, then you can still file this under normal F12 since the amount at €500 is small ( less than circa. 3K pa general threshold for self-assessment filing ) .

Thanks Guys for yere help. So I just want to clarify that it is possible for me to declare this money myself using the F12 form without becoming self employed.. As you can guess I am clueless tothis ............. As I want to avoid this route if at all possible.
Thanks