Instead of Indy coming out, Thumper surprised us and rushed right in. Indy was thrilled! After Indy lost her mother, she tried so hard to be accepted by the other outdoor (feral) cats. They rejected her and were very mean to her. So Indy used to stare at Thumper through the window before we trapped her.
Thumper and Indy sniffed noses right away, and then Thumper walked around sniffing the room with Indy following her, chirping happily.
The even played together for about 5 minutes, before Indy starting getting into hyper-active mode so we took Thumper out and closed the door.