Increasing

I am making a summer tank top for a friend of mine. She is small in the waist but very large in the chest. I am now at the part of the pattern where I will increase for the bust but I want to make it the next size up from where I started from. Here’s the pattern:

k4, m1, k to last 4 st m1 k4- so what do I need to do to increase by so many? (I began with large and want to increase to Extra large beginning with 123 st. decreased to 117 and now to increase it needs to be 147
If this is confusing to whomever is reading this it is “summer top to knit” on bernat.com:knitting:

You can do ‘short rows’, here’s a tutorial, you wouldn’t increase so many stitches beyond the 123. You could also knit the bust with larger needles which will increase the gauge and the measurement in the bust and probably wouldn’t need to increase as many sts either.

Thanks so much for the tutorial link- I’ll do that!

ok I watched the tutorialand another one on youtube but I still have some questions. Like how many rows do I make short rows into and do I have to do it on both sides of the flat work to make it even? Please help!

You can do it in the round, and how many rows of the short rows depends on the size. I thought that one explained how many by cup size.

Thanks again for the tips- I’m putting that project down for a while to finish some more urgent ones