I think you can accomplish a lot in 30 mins since you said it did not have to include phonics instruction. I have been homeschooling a DD 5 and 4 year old twin boy's this year. What about trying the following activities.
Calendar wall & review days of the week & ordinal #'s
Learn recognizing & writing #'s 1-30
Counting objects
Practice upper & lowercase letter formation
I keep lot's of craft supplies~scissors, markers, crayons etc... out for them to use anytime they like.
If you are not opposed to computer time, she could do Starfall or Time4learning while you are with the older children.
Read alouds at bedtime. :)