How to have parents join a Teams meeting for their disabled student when they do not have email

nonprofitschool ChristianBergstrom's suggestion of sending the Teams meeting link using other communication methods is a good one. Another alternative that a number of our teachers use for younger students is to have parents login to Teams using the child's account. Teachers create a private channel for each student (note, there is a limit of 30 private channels per Team including deleted channels for 30 days) then put a post in the channel with the scheduled meeting time then use the Meet Now function in reply to the post in the private channel at the time of the meeting and parents are able to just join the meeting from the channel.  You could also create a recurring, standard meeting and invite the private channel using the email address of the channel. This will create a post in the private channel with the meeting details and a link to 'Join the meeting' that students can use to join the meeting.