Twin bed

Is a 2yr old too young for a twin bed? We are expecting baby number 2 in November when baby 1 will be 25 months. Then 6 months in our room before moving to the crib. So baby 1 will be 2.5 almost before she gets kicked out of the crib. Our current crib converts to a toddler bed but I don’t want to buy another crib and i don’t want to buy a toddler bed for just a couple years and then a twin for our oldest. At 2.5 can a toddler use a twin bed or should I bite the bullet and buy another bed and crib mattress??