Nobody can help? XiaoBaitu please help!

Thanks!

My friend wants to start working for new company full-time ASAP by transfering her current H1 to new company,
and still wants to work for current company as part-time, so she needs to apply a new part-time H1 from current company. Can she start (or keep) working as soon as she submitted the new part-time H1?

Anybody has the same experience?

XiaoBaiTu, any ideas how to do this? Thanks in advance!