As boring as it sounds, it can be either, I’m sure some parents drive wedges between siblings by anointing a golden child vs black sheep, or parents could try and cultivate a loving relationship but the siblings just do not mix naturally, complete opposites to one another, think of that scenario like work colleagues, sometimes we just don’t like one another.
I strongly believe that no one owes anything to another human just because they are related, I think we would all have much better lives if we lived by this rule. I haven’t been in contact with my sister for a decade, and before that it was patchy as adults, we did try though.
She is nine years older than me, and I know from the moment I was conceived, she resented me. She took my mum on a roller coaster when pregnant hoping to be rid of me, she used to dig her nails into my hand while I was in my cot until I screamed. A few years later because my parents had to work she was left in charge of me, she would mentally torment me, scream at me, until I was screaming, then bribe me with a tracker bar, which was my favourite so I didn’t tell, there was some physical abuse as well.
She had this narrative that I was the favourite child, I’m sure it could come across like that, as she was boisterous and I was quiet and shy, so kept my head down, but the thing is, we still had the same floored parents, they did their best but I had my own issues with them. For example, I wasn’t the child they expected, I was shy and sensitive, when apparently i should have been adventurous and a little rouge, I was called soft, a tart etc, I’m sure you get the picture.
I think there are reasons behind some of my sisters behaviours, but instead of helping me and being close, she was just a bloody psycho to me, and it never improved, maybe small windows of getting along as adults. But then 10 years ago she slandered me on Facebook out of nowhere. I started getting messages from ex colleagues and old primary school friends, she was contacting them and saying awful untrue things, and that was that, I’m done forever!
She and other family members have tried to heal it, but I’m done, some seem to think I should forgive, they say daft things like ‘I don’t know what happened between you two, but she’s your sister’ and other such pointless stuff. It reminds me of the injustice as a kid, when another kid starts on you and the adults won’t listen that it wasn’t your fault and just say ‘I don’t care who started it’, but it wasn’t your fault, but your still in trouble!
With siblings OP it’s a very random lottery, if you want another, then go for it, but do it because you want it, don’t ever think it will automatically be a lifetime friend for your first child.