1、她所持有的在留资格决定了你发的邀请函是无用的，因为不认可她的这个权利，发与不发没有意义。不过如果是日本人发个邀请函还是很有用处的。
2、你可以办理旅游签证前去，自由行或者跟团都是可以的。很方便，旅行社轻松搞定。
用于办理签证的邀请函范文
Att. Sales Engineer
Date:
Subject: attending the meeting
Dear sirs,
We are very pleased to invite the Sales Engineers of our collaborators in England the company XXXXX(公司名称) to China from xxx(日期）to xxx（日期）for visiting customer and attending the meeting.
Name Passport No. Date of birth Title
We are looking forward to meet you very soon and wish you a successful trip.