Au pairs are responsible for organising and paying for their own travel between their home and the host family's country. Families from Switzerland usually pay the Au pairs travel costs. From the port/airport of arrival, both organising and paying for travel is the responsibility of the host family. You must arrange to meet her or arrange for a taxi to take her to your home.
finish the letter with "Yours sincerely, ", and add your signature and then print your full name underneath.