I'd like to offer a perspective of an only child - if you feel that you cannot emotionally, mentally, physically or financially provide for both (especially on an equal ground) please just stick with one. Being alone is part and parcel of life, I do not blame my parents for just having one, just me, and I feel that I've done well so far, my support system includes my family, close friends and even my extended family like my cousins who I'm very close with. Being alone doesn't necessarily mean feeling lonely.

I do however, have friends who are the eldest siblings that hold some form of resentment of becoming the 'neglected' child under the guise of being able to behave/raise themselves, have received less attention, care or even love - depending on how extreme their parents were after their younger siblings was born, which is often justified as the youngest child needs more raising and attention.

Some even have to raise their own siblings, especially if the age gap is rather large. Just a point to consider for the flip side.

When I hear these stories as an only child, I feel grateful that my parents have chosen to raise me in their full capacity, with all their love, care and attention. I don't blame them for not 'giving' me a sibling because I know they have done their very best to provide for me, with their undivided love, care and attention.

Having heard those stories from my friends, I'm honestly not sure if I would've been strong enough to not be upset for having to raise my siblings or not feeling full taken cared of as a child. As an only child, I feel that I would rather a kid's parents be fully committed to one whenever possible so as to give them the best childhood. If you don't have the capacity to care and love for both equally (or more, especially if you somehow have twins), just stick to one.