Lots of recipes here, may or may not be useful for you:

Celebrating Ramadan

For suhoor, iftar and Eid al-Fitr, recipes for your feasting table.
Chicken, Kibbe, Lamb, +++

https://cooking.nytimes.com/topics/ramadan?

https://www.democraticunderground.com/115764768

But I'd make sure it's been approved as "halal". Same for chicken, I suppose.

Today I went to a Costco Business Center where they sell frozen whole sides of lamb, marked halal. There wre generally persons of evident middle eastern descent inspecting them. I like lamb but a whole side of it is too much for me :=).

When I went today I saw something that is relatively rare... two men and two women. One of the woman was wearing a head scarf, no big deal. The other one was wearing a full chador, head to toe in thin black fabric, just a narrow slit for the eyes. I don't think I stared, but I did wonder... "doesn't it get hot in there?". However I refrained from asking. They were minding their own business and so did I. I was glad that nobody seemed to be bothering them, either. Afterward I figured the thin black fabric acted more like a sun shade than a heat retaining garment, and might actually keep the wearer cooler than being exposed to the sun on a hot day.

Anyway, yes, good on you for thinking of a welcoming gesture. Perhaps just knocking their door with a verbal welcome would be a good start, maybe with a "God Bless You" as well. Perhaps a housewarming gift like a potted plant?

Safest bet is chicken, fried or grilled.

Kentucky Fried Chicken does big business during Ramadan. In Malaysia it isn't unusual to find two Kentucky Fried Chicken on both sides of the road at the same cross street. I remember eating at a Kentucky Fried Chicken at Ramadan and the whole restaurant was waiting for the minute to start. They all were looking at their watches and trying to figure out who had the time that would allow them to eat at the right (and fastest time)

If you arrive just after the time to eat they will know that you took the effort to research it.

http://irusa.org/prayer-times/?gclid=Cj0KEQjwx6TJBRCWtsiXpI7bhOYBEiQA1en3F7uLm7zzmA8HTuUHNF1YcoCbiiPKf5Gr46B51I_wt5IaApVh8P8HAQ

I would caution against casserole with rice because sub continent and Asians are used to rice they have grown up with and may find the rice you use unusual. (American rice is hard compared to Thai rice and Japanese rice is wet to the Thai taste.)

You are to be applauded for being so thoughtful, wish you were my neighbor.

edited to add:

I don't think you should be overly cautious or worry about doing anything that is potentially offensive.

The will know that you made a special effort to provide something that are a lot of people would be too reticent to try but the fact that you tried to do something that is common to every day life will be appreciated. I know that the Muslims in my family would be absolutely delighted, they will tell all their friends about it for the next year and will wonder what you might bring next year. In the meantime they will respond to your hospitality by a factor of 5.

Good luck.

Sunset is bout 30 min from now, I'll take it over pretty soon.
Thanks for the advice

I would not bring any meat product, as if they are observant, if it were not properly slaughtered, it would not be something desirable.
Fruit would be best, cucumbers, watermelon or some fresh fruit. Water is always welcome and useful.
It could depend on the school they follow, but many would not eat foods flavored with things that have alcohol, think vanilla extract or other things used in baking.