Question for you guys...

I'm tutoring a Grade 9 student in math and she asked if I could help her go over some chemistry. I took chemistry right through grade 12 but that was 8 years ago and haven't looked at the stuff since. I know she needs help with lewis dot diagrams and I'm reteaching myself the material. It's all straight forward and I'm comfortable with it, but then I came across ammonium chloride.

So, in my understanding, an ionic bond needs to have a non-metal to form. But NH4Cl is ionic, despite being formed of three non-metals. Why?

Also, what would the lewis dot structure look like? Google is showing me about 5 different images and none are really well explained.

Finally, but probably most importantly, is this something that would be taught at the Grade 9 level or is this more advanced stuff that my student doesn't need to know yet?

From the worksheets that she's shown me the type of stuff they're doing in class is like... CH3BR, NO2-1, SO4-2, NACl, NBr, that type of basic and straight-forward stuff.