Is it weird to ask this after the interview?

My current nanny kid is starting part-time prek next week, and so I've been searching for a new family. I did a phone interview earlier this week with a potential family with three boys, and went over yesterday for an hour or so to meet them in person. They explained that their 2 year old has a speech delay and goes to a speech therapist to assist with this. Today, I sat down to send a follow up text after our meetup, just to thank them for having me over and tell them to feel free to ask for anything else they might need from me (references, etc). I think the interaction yesterday was promising, but I get the impression they're still interviewing multiple candidates. I wish I would have asked yesterday, but when thinking about it today I wondered if they had used baby signs with their children at all, since I've found it to be an enormously helpful tool with children before they're verbal, and I think that could be a helpful avenue for their toddler. I wouldn't hesitate to bring it up in person, but is it weird to ask that in a text when it's original purpose was just as a follow up to having me over? Does it sound a bit like...idk how to word this, but I may be suggesting an obvious solution to a problem they've dealt with for awhile? Just wondering what you guys think?

(Anyway, can you tell I overthink things at this stage?)