First of all, you shouldn't self medicate. It is not advisable as most people tends to get it wrong eventually which increases the risk of complicating medical issues. The best, in most cases, is to visit an hospital and seek the expertise of medical professionals.

Secondly, calamine lotion is an antipruritic agent. This means it is only meant to alleviate the itchiness associated with the chicken pox rash. There are still other symptoms which won't be eradicated with the singular use of calamine lotion.

Antibiotics will be needed to stop the infection. If there is fever, paracetamol or ibuprofen will be fine too.

Nevertheless, remember to consult a professional before choosing an antibiotic.

Yes

Ensure you limit contact with the infected person as much as possible. Try and separate him/her to limit contact with other members of the family. If you can get Chicken pox immunoglobulin, that will provide excellent temporary protection for your baby especially but it is scarce and generally expensive. Do your best and pray for the best outcome.

Chicken pox is a viral infection.
Please visit the doctor for proper management.

You have to try and separate her (your niece) to limit contact with other members of the family especially your baby.

Dear mom, yes the woman is right.this is the schedule for
The NPI vaccines and their schedule are as follows:
⦁ At birth……BCG, OPV, HBV
⦁ 6 weeks…..Penta, OPV
⦁ 10 weeks…Penta; OPV
⦁ 14 weeks…Penta, OPV
⦁ 9 months…Measles, yellow fever
⦁ Vitamin A recommended every 6 months from age 6 months to 5years
Non NPI
PCV – usually given along with the Penta and OPV at 6, 10 and 14 weeks
⦁ Rotavirus vaccine – usually also given at 6 and 10 weeks; some given second dose at 14 weeks
⦁ MMR – First dose at 12 – 15 months; Second dose at 4 – 6 years
⦁ MCV – usually given at age 2 years (can be administered from age of one year)
⦁ Varicella vaccine

what are the things you observed in your baby that makes you feel he has contacted Chickenpox? I mean the symptoms he is showing.

Who made the diagnosis of chicken pox? She should go to the hospital and let a doctor make a proper diagnosis and proffer an appropriate treatment plan for her.

Try and separate baby to limit contact with the sister. Separate their bed, towels, clothing. If you can get chicken pox immunoglobulin, that will provide excellent temporary protection for your baby especially but it is scarce and generally expensive. Do your best and pray for the best outcomes.