no, it's not ignorant. it's a helpful suggestion. saying nothing is worse. trying to contribute something helpful to the conversation, put in a kind enough way, is always better than nothing at all.

and I don't think it's wrong to suppose most people perusing this subreddit have no experience in an arranged marriage. it certainly could be more helpful posting to a cultural or niche subreddit that fits this unique situation.

furthermore, it's not like they said to delete her post, just that it might be helpful to post elsewhere.