Owlie's up for her second surgery today

[Traci]

She can be safely spayed while in heat, but it's ideal to spay when she isn't in heat.

If she's 4 years of age, chances are, she did go into heat and you didn't notice because she was too ill.

I don't think you need to worry about her eating too much at this point, judging by her pictures, she looks underweight. Nothing wrong with free-feeding....at some point in the future, when she heals and gains a more appropriate weight, you could consider scheduled feeding, but for now, feed her as much as she wants.