No. A pending or approved I-130 petition does not permit the beneficiary to remain in the United States if an immigrant visa is not immediately available. I am not sure what you mean by "SIL", but if it means sister-in-law, you should understand that only a U.S citizen brother or sister can file a 4th preference visa petition, not a brother or sister's spouse. You should discuss visa options, the possibility of your employer's filing a PERM labor certification application before your H-1B maxes out, and the possibility of your departing prior to the end of your H-1B to see if you might be able to return sooner and get additional extensions of H-1B status if the PERM is pending for 365 days or more. This is a complex area, so get a consultation soon with a very experienced and knowledgeable immigration attorney.
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