What family members should apply for tourist visa

[123kk]

Hi All,

We recently had a baby and my mother in law and sister in law want to come from india to see him. My sister in law is 25 yrs & unmarried. My mother in law should definitely come, even though sister in law can't come. Who all should apply to have better approval chances for mother in law -

a) applying for whole family ( mother in law, father in law , sister in law, brother in law)
b) just apply for only mother in law and sister in law
c) apply for mother in law and father in law ( in case just applying for mother in law won't be OK)

Is it better to self sponsor or we should sponsor from here

Also is it better to give visit reason as ' baby ceremony' or just ' tourist' ?

Thanks