Thinking..... any way you could keep her awake until you come home & do an earlier bedtime instead. Its just that its kinda messing it up if she's taking a mini nap so close to bedtime. Is she not napping at daycare cause there's too much distraction? Could you try maybe bringing something from home that would comfort her at nap time? Are they still attempting for her to nap?
The wi/wo method is in the link I sent you. Once you lay her down, you leave & if she starts crying, you count to 5/10/15 (depending on her temperament) & at the end of the count if she's still crying, you walk in, reassure her that evenrythign is ok & that its bedtime & you leave. Again start counting (if she's crying) & if she's still crying at the end of the count you go in again, repeat.... until she is asleep.