This morning, Amy said two sentences with grammar that she hadn't (to my memory) used before!
I heard her stirring so I went up to her room and asked what the matter was, and she said, "I want Mummy to come". When I asked what the matter was, she said, "I don't want to tell you that."
Previously, she would have said, "I want that Mummy comes" and "I don't want to say that to you", respectively—influenced, no doubt, by German: German syntax in the first case (which uses an explicit subordinate clause introduced by dass rather than English "a.c.i."), and German vocabulary in the second case (where sagen corresponds to English say or tell depending on the construction: etw. jm. sagen = tell s.o. s.th.; etw. sagen = say s.th.).
So I was a bit surprised, but quite pleased that Amy seems to be acquiring these constructions in her English.
Relatedly, it's seemed to me that Amy is no longer quite as averse to using German words in her English as she used to be. Before, she used to keep the languages as separate as she could, and if she didn't know an English word she would rather not say anything at all.
But now there are some German words she'll use more or less regularly in her English, such as "immer" (always). She also recently called a kite a "dragon" (influence from the German, where Drache = dragon, Drachen = kite), whereas she had previously always used "kite".
Ah well. I understand her, and she still speaks overwhelmingly predominantly English to me, so I'm fine with it; I'll see whether she'll "grow out of it" herself just as she's grown out of mistakes in English over time simply by hearing the correct version from me.