... "this a way"? Methinks it's supposed to be "this way", but I'm not 100% sure.

MarqFJA87 said:

... "this a way"? Methinks it's supposed to be "this way", but I'm not 100% sure.

That is fine and validates that "this a way" is too American.

Can't (and in this case shouldn't) わかった be translated differently? In a context like this, I'd see it meaning something along the lines of "got it" or "understood".

Commander_Rocks said:

Can't (and in this case shouldn't) わかった be translated differently? In a context like this, I'd see it meaning something along the lines of "got it" or "understood".

Not really, it's all about context rather than sticking rigidly to what the text says. Wakatta literally means 'I have understood' so in the context it's being used and based on what Nonna said, the current translation fits quite well...she's saying she's well aware that in that situation that Nonna would wash it out for her.