I would imagine that her chapter would allow this.
When I was in school a member had a boyfriend who was an independent and didn't go to our school - he gave her a promise ring and she was allowed to have a candle passing as though it were a lavaliering.
At my school once a sister was lavaliered/pinne/engaged she contacted the ritual chair, who was responsible for organizing the candle pass. I would imagine that your daughter could talk to the person in charge for their chapter and explain the situation.
Congrats to your ZTA!!
~Allison