Blind date girls don't answer their phones or text messages.

You can ask your colleague's sister-in-law to do the work. After all, she is also an introducer.

You can explain directly to the introducer: this girl doesn't answer my phone calls and rarely returns messages. Is she introverted or shy or has other attitudes towards me?

Ask her to help you convey this message to the woman's parents. If they still want to contact.

Just show your attitude to girls: after all, more contact can help you understand whether the other person is suitable or not. You can send a message to tell her.

I think: to a great extent, this girl may be shy. But this is only my personal guess. If you want to know each other's thoughts, you'd better ask clearly.

Work hard. Don't worry about emotional problems, take your time.

May you find the right person!