Advice on B2 visa

[immihelp]

We r planning to visit US onB2 visa on self sponsor category.My sis-in-law is a citizen and housewife.As we r applying on self sponsor category is it necessary to get an invitation letter from her.I am a Govt servant and my husband has his construction business.We have 2 kids aged 10 & 12 yrs old.I need advice on the following:
1.Can we apply for B2 along with kids.Our duration of stay is only 1 month.
2. How much bank Balance must be shown.
3.I have aged parents so I have to return within a month bein the only child .Is it adviceable to apply with kids or just the 2 of us.

[immihelp]

If you are self-sponsoring, invitation letter is not required.

1. Yes.
2. There is no precise rule. Enough money to take care of the expenses.
3. Either way.