I'm stuck on this. The ideas I've come up with has gotten repetitive- mostly revolving around warmth and familial love. It can range from description to dialogue. Thanks for your inspiration in advance! I'm new and excited to read your responses :- )
This is way too broad, it's like asking "How would you describe dogs?" What are you having trouble with specifically? Maybe you could post the part you're having trouble with in the workshop (you'll need to first do 2 critiques on other people's work). Or tell us much more specifically what the problem is.
If you do have a loving, caring family don't overdo it. People know happy families exist in fiction only to set up a plot that destroys their happiness.
A couple of suggestions: They stay in touch, often offering help if someone in the family needs it, or just meeting up to have a chat or share some gossip. Rather than being passively friendly, show them actively helping each other with no concerns about convenience or repayment. Maybe have a character from a less happy family see them together, and notice the difference.
I'm currently working on something similar. Not sure if my advise is "good" but it does make sense to me, so take it or leave it. First thing to keep in mind is, don't say they're a loving family, just show them being that way. Take whatever traits you'd consider to express familial love and let it define their interactions. Do they show concern for one another? Offer help? Embrace each other despite the hardships? When it comes to any loving relationship, it's vital to highlight the characters' bond in spite of what sets them apart and causes friction. So ask yourself what interpersonal challenges the family has to overcome whenever they interact. Their love will shine all the brighter if it is earned through mutual effort.
Loving family interactions often involve a lot of encouragement and interest in each other's lives. You haven't told us the ages of the family though. Are the kids little or grown? Are both parents still alive? Are there grandkids? How old are they? These things would make a great difference in the more specific advice we would give you. For instance, two grown kids would have a concerned conversation about a parent, whereas a young couple with kids would be shown nurturing their children in specific ways. We need more info, and we can give better examples and advice.