I guess to me I just don't see her as an "immature child" even if she's very spontaneous and at times selfish or ego driven, but in a way that still came off like an adult woman. Compared to the New 52 I'd say 90's Selina was a lot more mature (although she's not the only character who that would apply too).
I thought Loeb's Selina was okay.
I feel like Brubaker conveyed how much passion there still was between each other and how much they cared for one another, especially compared to their interactions with other characters or lack of conflicting love interests. But that's just me.