You can have someone else like cousin/relative or an adult to assist your family/younger sister to handle your toddler while you are in labour with husband. Since you mentioned you're contemplated with the younger sister and your mum's health issue. This is the best option since we can't bring kids to hospital. After you are discharge then you can have them back with you provided there's still helping hand as you need to heal very well after giving birth.
Get a babysitter. They are apps for this