530 GMAT score.

One other idea here is to apply to January term for Columbia when the application comes out in June IF you can bring up your GMAT to at least a 660 with a good quant score, 70% and MBA Math on top of that. January term is appropriate for those who do not need an internship such as entrepreneurs. The deadline is in October but only fools apply that late - apply as soon as possible, as soon as you have a good test score. They have rolling admissions.

This is the only top school in the US with a January intake. You might also look at other schools with January intake in Europe such as INSEAD, HEC and/or IMD. Ivey has a lower GMAT requirement but it is the top school in Canada; you might shoot for R3 in July and that program starts in March.

To be very honest I do not think you will have a good enough GMAT score in time for Round 3 deadlines; Round 3 is already extremely competitive as it is, the standards are already much higher. It helps that you are a female from Kenyan, but it's a risky move. They still need to know you would succeed in the classes.

Would advise January or March start or just take all this time to sort out the GMAT and up your application quality to ensure your success by applying to round 1 for next year.