Girl $1$ and Girl $3$ are saying contradictory statements and so if one is false other must be true. Let Girl $1$ say the truth. But this will make Girl $2's$ statement also true which will violate the "only one true statement" requirement. So, Girl $1$ can't say the truth and so let Girl $3's$ statement be true. This means Girl $2$ must say lie and that means cat must be in Girl $2's$ house.