Not a day goes by without him mentioning it. Mommy, when am I going to have a baby brother? he asks, his eyes filled with hope. At first, I thought it was a phase, like when he wanted a puppy, but time has passed and his desire hasn’t changed.
It breaks my heart because it’s not that simple. Sometimes I tell him that babies don’t just come, that it’s a big responsibility. Other times I try to explain that we’re fine like this, that he’s enough for me. But he insists. He tells me how he would play with his brother, how we would share toys, how he would never feel alone again. And that’s where it hurts the most, when he mentions loneliness.
What if what he really needs is more connection with other children? More cousins, more friends?
Omg, my daughter did this for months when she was around that age. Every morning, every night, she would ask when she was getting a little sister. She even started naming her imaginary sibling. I totally get how heartbreaking it is, especially when they talk about being lonely. What helped us a little was setting up more playdates and hyping up her friendships. It didn’t make the wish go away completely, but it gave her other little “siblings” to love. 
My son went through this, and what helped him was making him feel like a big kid in other ways. I signed him up for a music class, involved him in helping out with his younger cousins, and talked a lot about how great it is to be an only child sometimes: extra attention, being special, trips, choosing dinner, etc. I keep talking about having a sibling, but I’ve also started to appreciate the perks of being an only child. Maybe it’s worth a try!
Developmentally, 2 year olds are just beginning to understand relationships, and the idea of having a sibling is very appealing because it feels like an innate best friend. If the real issue is loneliness, you could try sibling interactions, like playdates, the same children, and the same routines, to strengthen that close bond. Additionally, social stories, books, or simple explanations about different types of families can help. And if they need comfort, some children respond very well to a special stuffed animal or an older, child role, such as helping care for a pet or a younger cousin
I went through this exact thing! My son was so fixated on having a baby brother that he would literally set a seat for him at the table. It was honestly hard for me too because we weren’t sure if we’d have another, and I hated seeing him so set on something I couldn’t promise. What finally helped? More structured peer interactions. I found a weekly toddler class, and we started meeting the same group at the park regularly. Having familiar sibling, like friendships helped. Also, I started playing out scenarios with him, What if your best friend was like a brother? or What do you think a baby brother would do all day? That got him thinking more realistically and made it less of a fantasy. It didn’t completely stop, but it definitely helped. Hang in there, mama.
When he was 2, my son constantly asked for a sibling. Now, at 5, he’s begging for peace and quiet, haha! One thing I wish I had done then was consider the importance of finding family connections. Spending more time with immediate family, meeting up with regular friends to play with, maybe a toddler group at a community center. Sometimes, they simply crave that social space, and more structured ways of connecting with other children could help fill that void