Visitor VISA Query

[vnarahari]

Hi,

My MIL is currently in the US beginning April 20, 2012. Her I-94 expiration date is October 19, 2012. My wife and I would like my MIL to stay until May 31, 2013 next year.

The reason being, I am due to be transferred to UK sometime in October 2012 and my wife who is in school will only finish by May 2013. Between October and May next year, my MIL has kindly offered to fill in the gap and take care of our baby.

Now I have browsed through several forums and I have learnt that there is no gap time specified by the USCIS. However, it is preferable to have atleast 3-4 months gap between successive visits. I am confronted with two options:

1. File an extension for my MIL using I-539. With the hope that it gets approved, my MIL can stay until April 18th, 2012. I will still have to figure out a way to fill the remaining 1 month gap.
2. Have my MIL and daughter travel with me to UK. Stay there from Oct 10~ Dec 5. Then have my MIL re-enter the US to get a new I-94. If she manages to get re-entry then great. If not, then it is quite a bit of hassle.

My questions are:

1. If my MIL was to have her extension rejected, can we still pursue Option #2 i.e. have my MIL travel to UK, stay there for a month+ and come back to the US?
2. While nothing is 100% sure, which of the two options is better? Does anyone out there have similar experience?

Any input from you people out there is deeply appreciated.

Thanks
Narahari