Um George Boleyn most likely never had sons especially ones named Thomas and William. The George Boleyn of Elizabeth I court was most likely a distant cousin not from the main line. Also if these are hypothetical children why is one named William? Also just shooting out a couple of what ifs on how to make the Percy's even richer since with her siblings lines gone there would be nothing stoping Anna from sueing her cousins for the wool earls English eastes. Also with wool earls eastes the north wouldn't be laughing at her from being deceased from mercthents. Also didn't the 5th earl of Northumberland provide some means for his younger sons? They might treat her with respect with her being an heiress. Also she probley it's probley going to be easier for her to clear her husband debt with her eastes.Without Anne's "fall" in 1536, odds are the Boleyn inheritance is going to George Jr, son of George and Jane (the wife who erroneously always been blamed for bringing up incest - there's no proof in the testimony that effect). Or maybe one of their other sons: Thomas, or William. Don't be greedy for Anne; she'll make a man of Percy, and her biggest worry will be to whom to wed her precious son. (Who won't be near as clever as Elizabeth in the OTL.) You are probably right that she'll straighten out the mess Percy's made of things; but going to court won't be 'awkward' once she has the baby. She and Henry will merely be courtly flirts and that will be the party line they both put out.
Her brothers-in-law will mean less to her than Henry VIII (after she learned of the baby). Percy is the one who matters. If they don't follow her (and Percy's) lead, she'll leave them to fend for themselves and won't give them the time day.
Also no earl of Northumberland as clever as Elizabeth I? That sucks I'm a big Percy fan so I would have enjoyed a dynamic earl of Northumberland. Also wouldn't Anne be bitter at Henry viii for still sleeping with his queen and might say somthing stupid that gets her banished from court? Or the queen wouldn't want the last of Henrys fancies around from before she gave them a son and has her banished. Besides a break from court would really cut down the exspesess and if she wants to get rid of that debt cuts are needed.
Also what heiress is available to Anne son if he was born in 1530. With her on a make her family rich kick she probley wouldn't settle for less.