Amy's fricatives

Amy seems to be working on sorting out her fricatives.

She seems to have most difficulties sorting out [f], [s], and [S]; for example, she certainly has [f] in [fi] (Miffy), but "fish" is [SIS] (though her [S] is not quite my [S]; I'm not entirely sure what it is in IPA, though).

"Sophie" used to be ['fifi], but is now ['fisi]—so she's got the right fricatives now, but in the wrong order! (This also means that the vocative forms of "Sophie" and "Miffy" are now distinct :))

She also has [X] and [C] down (German Ach-Laut and Ich-Laut—probably allophones of one phoneme, say, /C/), in words such as [?oX] "hoch (up)", [bUX] "Buch (book, though with wrong vowel length and quality)", and [lIC] "Licht (light)".

For some reason, it amuses me that such a small child can pronounce [X]; I'm not sure whether that is because I consider it, somehow, a difficult sound, or whether it is because I talk to her in English and it's traditionally a difficult sound for monolingual English speakers to master.