Lining going into transfer

So I’ve been struggling to get my lining thick enough to do my FET. A few weeks ago it would not grow past 6mm, and subsequently we had to cancel that cycle. This time we changed the med protocol and at today’s ultrasound my lining is at 6.9mm, and they scheduled me to do my transfer next Friday, I will trigger tonight. My question is, has anyone had a lining around 6.9 or seven and had a successful FET? I told my provider that I was a little worried that it wasn’t thick enough because they kept saying they wanted it between 7–8 ,but she reassured me that it will be OK to move forward with the transfer. What are your thoughts?