Eh, similar, but definitely not the same.
'Nido aru...' is more of a warning, like, "bad habits will keep happening if you're not careful."
'When it rains...' is a fatalistic statement, that it's all going south and there's nothing you can do about it except wait it out.
Contextually, she is talking about her own shortcoming in failing to listen to the advice she's given, and she uses the idiom to indicate that she does have to be careful, or else she will continue to experience these mishaps. 'When it rains...' does not make sense in this context at all, because that's not what she said.
You can extrapolate that to mean whatever you want, since y'all are clearly determined to make this into something much bigger than it is and turn it into a whole metaphor about how the soup represents the two paths of romance and idolhood and how she has to choose just one blah blah blah but ultimately she does not really regret her decision to get two soups (she loves her soups, that is the true takeaway in all of this), nor does she indicate any particular sense of frustration, anger, resentment, or any hint of being upset. Leave her soup alone.
