Nnnn I don't know how I feel about this

Some of the things she's said in the past would make me think she wouldn't even consider something like this. But ok Marina 😑

Omg please DDGG is coming

This does not even remotely insinuate a collaboration or a desire to.
She would never collaborate with her and if she did I would not support it.

Give Marina her first hit Katy

Please collab

YASSS Marina please collab with the Queen of Pop, she could give you your first US hit! Omg hope it happens someday

This clearly says that Marina is open to work with Katy and that she has hanged out with her so they're friends

I am sorry you won't support something that has not even come out but other people would, so no worries!

her boob

hahaha oh my god sweetie... awww you're so determined

No. It was a vaguely polite answer to a cliche question.
They are not friends. Marina opened for her tour and she says here "Katy treats her support nicely" and invited her to one 4th of july party that year to which Marina admits she never spent much actual time with her. They were work colleagues, acquaintances.