My parents had my younger sibling with a 15 year age gap, when they were 39/40. And my mum has told me it was the worst thing she's ever done. She brought up me and my other sibling in her early 20s pretty much alone, and said it was a breeze compared to having 1 at 40. dsis has basically been an only child growing up, has caused huge amounts of stress and upset for my parents, at school and at home, and the teenage years have been hell for all of us. We all love her to bits, but my god, she's been difficult. Me and my similar aged sibling were always good kids, did well at school, etc but youngest sib has been so so different, and I don't think my parents ever could have imagined going through what she's put them through, now in mid 50s and dealing with the police knocking on the door, and endless dramas and issues at school. They're exhausted and truly fed up, and they should be looking forward to retirement. Instead mum has been doing the school run for the past 25 years, and has felt really isolated as all her friends she had kids with in her 20's just can't relate. Me and other sibling are grown up and moved out years (decades!) ago, so really they should be enjoying their time as grandparents, who can give the babies back, go home and relax, but instead they're dealing with teenage dramas, and constant issues. They can't even go on holiday as she will refuse to go with them, as understandably it's boring being an only teen on holiday with your parents, but the one time she brought a friend, they got into trouble abroad, and she can't be trusted at home alone, so they literally never get to go away. It's a nightmare really, and one I will 100% be avoiding! I know everyone will have their own experiences, but just thought I'd share our families as it's been a huge eye opener for me. I know she's particularly hard work, but I guess dealing with any child in your later years will be harder than in your 20s/30s, so when they're a difficult child, its extremely hard. I've had to support them through so much, and feel like a second mum to sib rather than a sister, and we'll never have a proper sibling relationship due to the age gap. I feel sorry for her, as she probably did feel lonely and isolated growing up as basically an only child, but also having to rush around being dragged here and there with my mum taking my and older sib to and from clubs/school/etc, but without the rewards of siblings to play with when we got home as we'd be out with mates, or doing stuff she was far too young to join in with. I used to take her out when she was a baby/toddler, but once I'd turned 18, was working, partying, in relationships etc, we rarely saw eachother, then I moved out, and she was left effectively as an only child, with exhausted parents who didn't really have the energy for a pretty "full on" child. I'm sure it can turn out wonderfully too, but there's going to be upsides and downsides of it, and for my parents, if they could turn back time, I'm pretty sure they wouldn't have chose to have another baby when they did.