Nemi smiles as the tricky cat turns docile and follows Elric's lead. 

Seeing Tapdance relax, Elric does the same - to a much lesser degree - and holds his empty hands out, palms up.  Softly chanting and with subtle hand gestures he casts Speak with Animals, then sits down before the giant kitty and asks:

"So, you're a lovely one aren't you?  Do you know how little people like us can get help to grow again?"

Looking over to his friends, Elric says:

"She's going to be chummy for 24 hours now unless we upset her, and I can speak to her for about ten minutes; what else should we ask?"

Do you have a way to communicate with her? I'm not sure that animal friendship allows for 2-way communication with the animal, just makes it friendly to you. I may even allow that it can understand your suggestions/commands and want to obey them. But can it talk back to you from that spell?

Not to rules lawyer, but if casting Speak with Animals it depends on the intellect of the animal as to how much it can do, but the communication back and forth seems within bounds as I read it.

Horkur is hanging back, if food didn't make it like me before, not sure what I will do now other than make it hungry for or angry at me!

Speak w Animals for sure, but that’s a different spell 

Ah yes, sorry for confusion, you did cast that spell.

Tapdance purrs at you, “Silly morsel, I know you were big before and now you’re small, but I don’t know why.”

To avoid any potential kitty conflict, Nemi pats her pack encouraging Cheetah to stay within while she observes the interesting conversation.  (which I believe just sounds like a back and forth cat dialogue of mews and meows to them?)

"Elric, what about that invisible thing the critters keep mentioning in the house?"

(Sorry for the confused post DM, I cast both spells)

"Mmm yes, you're very observant" says Elric, trying to keep Tapdance on side.

"Do you know about anything that lives in the house but can;t be seen?  Maybe you smell it?"

To his friends, the cleric appears to be mewling and purring softly.

Tapdance arches her back and the hair along her back and tail spikes out, and she gives a hiss. "Nasty mean creature, master's special pet, always watching, very mean, I hate it. I can't see it but I know it's there watching, I can smell and hear it sometimes. Master sees what it sees, it spies for him... Usually it stays in the house."

Elric relays this latest detail to the team and asks them: "Anything else you think I should be asking her?"

(sort of spoiler-ish because my character doesn't know what she's saying but maybe offer to help her get rid of it?  It could be causing him to do these things.  We know he's going to ask her about it.)

"What about all the Purple eyes in the bees and lightening bugs?" 

Elric nods at his colleagues' suggestions, winks and turns back to Tapdance:

"We could maybe help you to banish this unseen interloper?  Do you have any idea as to how we might achieve this?  Also, if I may; we have witnessed a number of insects in this garden that bear glowing purple eyes, do you know what causes this or how it can be stopped?"

You get the sense that these concepts are a bit over Tapdance's head. She mews and purrs and murmurs, "Silly morsel, you talk a lot."

Nemi watches the area around and keeps Cheetah within her pack wishing she understood the unusual conversation. 

Elric looks at his friends, a little sadly: "I think I didn't account for her, erm, feline intellect"

Trying again he says "Purple insects are funny, why?"

Tapdance scowls and says, "They taste bad. Taste like master's work room, blech."

She stretches out her paws and flexes, claws deploying and retracting. They look quite sharp.

Horkur yawns.

"So is this guy gonna eat us?  Point bein', we may wanna figure out what comes next.  My vote, we figure us a way towards that koy fish, or quail, or whatever it is - and a place to keep us safe from tapdance here once your magics wear off.."

"She should be friendly for 24 hours, but yes we don't want to risk being around her when the magic wears off"

Elric thinks that they have as much from Tapdance as they will get, and it's time to get her a safe distance away: "We saw tasty morsels that way" (indicates opposite direction from their route of travel), "Hurry and you'll eat well"

Once the cat has left, Elric checks if everyone is ready to head to the fish pond.