Often people will say they are traveling on to Mexico or another country by bus if the questioning comes up.

6 weeks is not that long that it should be an issue but good you changed date just in case.

I agree with the documentation on child being legal to travel. I forget who but this issue came up recently for someone and they were glad they had the paper handy to show.

San Pedro based Belize Blog since 2007 - great travel resources & discounts https://tacogirl.com/