Becoming a partner

One of the older partners at our practice wants to reduce his hours. To cover the hours this partner will no longer work, we would like to offer our excellent salaried GP partnership status and a profit share, for the three sessions per week the partner is planning to give up.We want to do this as a gesture to show we value her services, and when the partner retires she would already have a 'foot in the door' to take on the full partnership share. However, will there be a problem with taxation if she continues to work her other seven sessions as a salaried doctor?