Sure, the old lady inadvertently ruined the surprise factor, but she was willing to listen to MC despite his suspicious behavior and even low-key ships Chii/Tomo.
Maybe she'll pop up again, this time as an active wingwoman.
@PotatoZero
Except for the likely 90% of times when nothing is happening she is likely the one invading your privacy and gossiping about you.
Her finding the bag and attempting to report it isn't the problem though. The problem is that even after finding the bag and having the situation explained to her, she then proceeded to completely ruin what was left of the surprise by snitching on the MC to her. Gossipy old women who can't keep secrets or mind their own business aren't exactly seen as paragon's of virtue.