Seven weeks away from mom is a lot for a two year old, but beyond that, going to a place that needs humanitarian work sounds risky.
One of our daughters has 2 kids, 2 & 4. We babysit often for oldest, the youngest less often, both occasionally. JUST ONE of them is a chore (wild child)...both is a struggle.
Don’t get me wrong. We love our grandkids and jump at the opportunity to babysit. But, we’re also smart enough to know the work involved. LOL
The mom leaving both with dad for seven weeks would be Hell on earth. Mom needs to stay home (not go on trip).