Thanks to all those who posted here and on facebook advice and encouragement.
This is just a really frustrating time, because at the end of the day I don't think there's much I can do. I'm not going to bite her back, but I also can't neglect Oli while he's awake and get down on the floor and play with the toy farm with Lily.
It's a rough season of give and take.
I'm thankful that Lily won't remember these early months and even years sometimes!
To deal, I've been giving Lily loads of attention during Oli's asleep times when she's awake (8am-10am, 2pm-4pm) and have tried being more interactive when I'm breastfeeding or bottle feeding Oli during one of his awake times (unfortunately the feed is 75% of his awake time) with her, but I'm limited to what I can throw her (toys, snacks) and what I can say to her (read aloud from memory her favourite books when I see her grab it, ask her questions, etc), because I can't be physically with her and feeding her brother at the same time.
She still tried to bite me and Oli's feet a couple times today but I gave her some wooden toys on place of my flesh as soon as I saw her coming towards me, mouth open, teeth glistening, and that seemed to re-direct her. She even spent some chow time nibbling on the chair I was sitting on... really makes me wonder how much is jealousy and how much is plain old teething (she still only has 6 teeth and many more are due). Seemed happy so long as she was biting something, though me and Oli are still her preference and only when they're awake together.
I also pushed her nap time from 11am to 11:30am so I get 30 more minutes with her once Oli is down. Normally they both went down at 11am, making his 10-11am awake time entirely about him, and then it was bedtime, with no time for Lily-focused play. Also means she wakes at 1:30pm (theoretically) and by then Oli is nearly done his feed that began at 1pm, giving me more time to share between them.
I'm basically trying everything, and I'm seeing progress, so I'm encouraged.
Lil and I had a bath today as soon as I put Oli down and it was really fun. Now she's playing with plastic containers on the kitchen floor as I make dinner, and I'm relaxed knowing Oli wasn't clawed today :)
Another day survived. As if I can claim that before 3pm...