Aragorn and Arwen's children's ears

[Maédhros]

but I don't think there is any evidence in the books to suggest that Elves had pointy ears to begin with.

Aside from the other contribution in this thread about elf ears, I have found this: From the Letters of JRRT: 27

I picture a fairly human figure, not a kind of 'fairy' rabbit as some of my British reviewers seem to fancy: fattish in the stomach, shortish in the leg. A round, jovial face; ears only slightly pointed and 'elvish'

I think that their ears would be a little pointed.