Connections watched on as Pretty Pollyanna took part in a six-and-a-half-furlong gallop at Newmarket on Wednesday morning.
She was guided around the famous course by Frankie Dettori and many were expecting her to line up at HQ next week.
However, owners Bill and Tim Gredley have now decided to skip the event, throwing her participation in the Qipco 1,000 Guineas on May 5 in doubt.
Bell said: ‘There has been a change of plan.
We are not going to run in the Nell Gwyn and we are just going to give her a bit more time and just reflect on a few things.
‘We will either aim her at the Commonwealth Cup (over six furlongs at Royal Ascot) or we might just go straight to the Guineas.
‘I will talk to the Gredleys, and we will decide whether we run in the Guineas or focus on a sprinting campaign, but we are yet to have that discussion.
‘We have not ruled anything out or in.
Hopefully the filly can have a really good season, like last season.’