Actually, her sentence wasn't that wrong. "They are so nice. They have kids as well." Grammatically it's not entirely wrong. "As Well" can depend on given information as well as inferred information. In this case she was clearly stating that they are nice and they have kids. The chat inferred that Henya was saying "They have kids (as I do), which really wasn't part of the conversation or immediate subject and thus the inference is imagined rather than implied. It's a nuance of English that can result in a formal speech tone playing out differently if taken as casual.
Yep exactly. Her English was actually fine. She was talking about how she felt awkward due to being caught off guard by them being outgoing and friendly. In that context the kids were mentioned as a contributing factor to her awkwardness and their pleasant and energetic greetings.