Need some advice on asking for a significant time off as a nanny.

Hi everyone, I just want to make sure I’m not being unreasonable when I request this time off. I’ve been with this family for over 6 years now and never really take time off except a few days here and there since a bulk of my pto I have to use when they go on vacation.

But I have the opportunity to travel over seas in the month of May with housing and food provided all I would need to cover are my flights. The trip in total will be about 3 weeks so I’m going to ask for 4 weeks and I’ll settle on 3.

I want to mention that I’ll be giving them 3 months or time to find help and I will also try and help to find a temporary replacement for that time. Im feeling guilty for asking for that much time off, but I feel I can’t really pass this opportunity up.

Any advice would be appreciated.