That assistant is way too into her own head. Like she just immediately assumed that because she doesn't have talent for the aspect of manga that isn't present in her current works, that she cannot do it at all. Honestly, if she just turned her "One off scenarios" into a 4-koma setting it would work perfectly, and probably give her the practice she needs to realize what she is missing. It's just that she rarely thinks of scenarios where a character has to consider something that happened in the past, which can actually add to the one-off scenarios she writes by letting her establish jokes/scenarios faster.