i think sub eva would be someone who values your commands above all else—even if they include embarrassing herself for you, it's for you, so she'll do it with only a little hesitation. she just really, really wants praise and to be called good and obedient by you. it doesn't matter if that includes just edging herself while you watch or if she needs to beg to not be allowed to cum, because your praise is valued above her pride.
that said, she's absolutely so embarrassed about everything, and it takes a while to get there. at first she's always closing her eyes, trying to hide her face and voice, etc. eventually i think she'd start liking the feeling, because it's always accompanied by you saying she's so pretty and cute and “you're being so good for me”. cue her keeping her eyes open just to feel even more humiliated by what she's doing.
alternatively, i think she'd love being blindfolded. since she can't see (you), a lot of her embarrassment disappears and she has a much easier time being more vocal. but even then, she'll still try to hide or keep her mouth closed, so tying up her hands and putting your fingers in her mouth is the hottest thing ever. or making her beg to cum in great, too. she can't just keep her mouth closed, and you can make her praise herself as much as you want. “well, only good girls deserve to cum, eva. have you been good for me?”
she's very determined to receive praise, but she's awful at accepting it or, god forbid, praising herself. whenever you make her repeat after you that she's a good girl, or so very pretty, or so brave for doing something embarrassing, she always says it back in a quieter way, and if you tell her to repeat it louder, she'll give you the meanest glare she can muster. (which usually ends up just being a pout.)
also, she's absolutely going to be researching about her specific kinks or turn-ons and making a little document for herself and only herself. that is, until she inevitably tells you about it, whether by being too drunk or just because she hopes you'll tease her about it.
you can have her sit on your lap, tablet in front of you both, and have her read everything she wrote while you're toying with her. when her conclusions are too short or she's skipping over lines, you can interrogate her some more about why she likes certain things and make her explain in more detail why she likes such dirty things. your voice being so close to her ears only makes it worse.
she's panting and quietly whining, just getting to the end of a paragraph when your fingers curl into her most sensitive spot. “hm? what was that? mind repeating it for me, darling?” while you're abusing that spot, making a mess of her.