All families are different in how they deal with issues that they aren't exactly sure of.

Some families are genuinely supportive, who actually DO behave in your behalf, (whether or not it's behavior that is comfortable for you at that specific time), they are acting on your best interests.

While there are other families who go through the motions of concerning themselves with 'your' specific issues, for whatever their reasons, (can be so many that it's difficult to even try to understand their reasoning of behavior). It would seem to me though, that these kinds of members, who 'say and seldom, if ever, do', would be doing more justice to the troubled member, if they'd just not butt in at all.

I'm from a family of "knowologists". They have this inside family joke, a "motto" if you will, which they all have deemed themselves so proud of, (still not sure why as I find it bothersome as hell)...."There's the right way, the wrong way, and the ("our last name") way".
Point being, arrogance and insensitivity with an enlarged ego have dictated their behaviors, (even toward each other, though they overlook it without regard), to the point that the things which truly do matter, such as a family member in genuine need, is more likely a target of judgement casted.

I can personally relate to how you are feeling. Feelings of insignificance, unimportance and perhaps even feeling out-casted. Took me years to finally accept the fact that, although it STILL hurts like hell, I'm better off constructing my own family of hearts, (friend's who know HOW to care), instead of settling with the bloodline I was born into.
(I swear to this day, I was born in the wrong family, and on the entirely wrong continent....lol).

You've had some good advice in your replies here.
Try not to receive 'all' of your sister's responses as cynical or impersonal. Surely, there has to be one member in your family who can be genuinely receptive of the real you, (although, I must admit, I hoped for that, myself, as well). And if the unfortunate reality is that you simply do not have that bonding within your family that you are in so great need of, then perhaps seek out those who can BE that family of hearts for you.

I truly wish you the best.

Shangrala