Tips for weaning 1 of 2 nurslings?

[poppys_mommy]

It's been a week, so I'm really hopeful!  I'd be happy being done with my 3 year old nursing.  The last times were pleasant, too (much more than they'd been in months) so I'd be thrilled ending on a high note.

She hasn't nursed this week because she's been sick and I have a no-nursing-when-sick rule (in the last few months) because she can't breathe through her nose and gets frustrated so there's just a lot of screaming and snot.  She's been ok with this rule.  Otherwise, she nurses ~5 times per day.  Morning, before and after nap, bedtime, and usually once at night.  So she didn't seem close to quitting and the few times I've mentioned it as an option, she starts crying hysterically.

BUT since it's been a week, I'm wondering if it might not be too traumatic to quit now.  I think when she is well and asks to nurse, I can maybe suggest other things (water, play, cuddles) and it might be ok.  I'm still nursing a 7 month old (basically exclusively) and I am home with both of them in a small apartment all the time, so she'll definitely see nursing. 

Any tips on how to peacefully wean an older one when tandem nursing?