A 2 year old child needs at minimum of 12 hours of sleep to function properly the next day and to keep them healthy.
The 2 year old might sleep 10 hours per night and then nap an hour or two hours during the day.
Some 2 year olds may need 14 hours of sleep with 12 hours of that sleep happening at night and then 2 hours throughout the day as napping.
When a toddler gets cranky during the day then the 2 year old needs to take a nap.
Getting the 2 year old down for a nap will help them be refreshed and then they will be less cranky.