D.C.
Ear infections are NOT contagious. The cold she had before the ear infection was (and is likely gone now), but the ear infection itself is not. After all, it's not like anyone else can be exposed to the goop inside her ear.
So, if she is acting well enough to go, you could go. But if she's miserable, then keep her home. No sense in ruining everyone's day with a fussy toddler who needs lots of rest.