Talking about the grandmother, I wished that she was smart enough to tell our MC the problem she's going to get by sticking by her best friend. You got yourself who can see such powerful monsters, and then your best friend who is effectively a fiery beacon for said monsters.
That accounted, thanks to what we're seeing in this chapter, I doubt the MC is going to find out about that capability any time soon, since MC actively ensures that her best friend avoids monsters - and I guess we'll never know exactly how much power her best friend packs (which might be a good thing - arguably, the main reason why she's still safe at this point is because bigger spirits don't know how badly they could be burnt, so even though she attracts monsters, only smaller ones get burnt).