A: Were you to sell your surgery share you would be liable for capital gains tax (CGT) on the difference between the sale proceeds and the original cost. If you retire at the same time as selling, you would qualify for entrepreneur's relief and this would mean you pay only 10% tax on the gain chargeable to CGT.
If you gift your 25% share, or receive a payment for it below its market value, HM Revenue and Customs (HMRC) would nonetheless deem that you have sold it at market value.
As your surgery stake is a business asset, you can jointly elect to claim hold-over relief. This defers the capital gain to your daughter and the deferred gain reduces the 'cost' of the asset to her. So if your share's market value is £100,000 and originally cost you £30,000, the capital gain is £70,000. By claiming hold-over relief, no CGT will be payable and the £70,000 capital gain reduces the cost of the asset for your daughter. When she sells the asset, the cost to her will be £30,000.
Hold-over relief means losing entrepreneur's relief and your CGT annual exemption, so get your accountant's advice.