Please forgive her slight self-centeredness; she was afraid that if she called someone over and they went into the pond to catch fish, causing something bad to happen, they might blame her.
Therefore, she left two fish on the shore and stashed the rest in the kitchen space of her "dimension," quickly making her escape.
The reason she didn't put the fish into the space's stream was that she didn't want to contaminate it. She wasn't sure if the stream water could purify itself, and if it couldn't, the water might get dirty over time.
After all, there was that pond by the waterfall, which was spacious enough to raise some fish and shrimp.
As Luo Qiao thought about the scene at the pond, she suddenly stopped in her tracks. Oh, she realized why the villagers had said it was hard to catch fish in the pond and that it was very deep, and nobody dared to go in lightly.