AITA for complimenting one friend’s child but not the others?

I’m a single woman in my 30s and I don’t have kids. Recently I went on a small retreat with two friends. One of them is originally from the UK and a single mum since her partner passed away. She has a 12-year-old daughter. The other friend is a coworker who recently moved here from India with her husband and their two sons who are 13 and 14.

Because of travel delays and waiting around we spent quite a bit of time together just sitting, talking, etc. During that time I couldn’t help noticing how calm and self-directed my UK friend’s daughter was. She had her iPad, books, and some puzzle type things with her, but instead of just playing games she was doing things like mental math apps, spelling challenges, logic puzzles, that kind of thing. She was also very polite to everyone and really curious. At one point we were chatting and she started explaining something about a science topic she was learning and talking about how she wants to become an engineer or scientist someday, not in a show off fact regurgitation way but genuinely scientific and critical thinking approach. I genuinely found it impressive and told her mum she seemed very intelligent and composed, and that I actually learned something from the conversation.

Meanwhile my coworker’s two boys were having a harder time during the trip. They were arguing with their parents, throwing tantrums about small things, talking back, and generally acting like anyone other than their dad had to follow their instructions. A couple of times they also made comments toward the girl that came off as pretty sexist, which made things a bit awkward but she handled it well and basically ignored it, stuff like implying she is stupid or that her talking about her hair and nails etc is dumb stuff. I didn’t say anything to them or criticize them because I didn’t feel that was my place.

Later though, my coworker’s husband said he noticed I complimented the girl but didn’t say anything nice about their sons. He said it felt borderline racist because they’re Indian and the girl is white and it seemed like I was treating her as special.

My coworker said she doesn’t think I meant anything bad and that it’s not as big a deal as he’s making it, but she also said they’re kind of used to people appreciating their kids less here. After that I tried to say something positive about the boys, mentioning they seemed very good with their iPads and knew a lot about the newest phones they were asking their parents for, but he still seemed annoyed.

Now I’m wondering if I accidentally handled this badly. I genuinely wasn’t thinking about race at all, I just complimented behaviour I happened to notice and didn’t comment on the other kids because they were struggling a bit and I didn’t want to embarrass anyone. AITA for complimenting one child and not the others?