Just don't know why she doesn't just say something like "I lost my memory don't tell anyone btw". Would fix the problem of the relationship and probably get her an ally. But she's either being thick or thinking so far ahead we just can't comprehend it.
If I'm not mistaken, she already confessed to having lost her memory to the other maids. Or am I confusing another story? I truly think that confessing the same to the count is the safest route.