The cost of the property for CGT purposes will be the sum of half the purchase price in 2009 and half its value in 2010 when you husband passed away. I'll use £270,000 as the cost for my answer. If HMRC allow the kitchen cost, that will reduce the gain to £70,000 (£370,000 - £270,000 - £30,000). The annual CGT exemption of £11,100 will leave you with a net taxable gain of £58,900.
The level of your income dictates the rate or combination of the CGT rates (18% and 28%) that you pay.
Your income in 2016/17 will be about £33,400 (NHS pension £28,000 + teaching £3,000 + rent £2,400). Your personal allowance of £11,000 will leave you with a taxable income of £22,400 which will be taxed at 20%. That leaves £9,600 of the basic rate tax band to be used by the capital gain. So, £9,600 will be taxed at 18% (£1,728.00) and £49,300 will be taxed at 28% (£13,804.00). The total CGT liability will be £15,532.
If you sell the house in 2017/18 (after 5 April 2017) for the same price, you may pay less CGT as your income will probably be lower. If you only had your NHS pension of £28,000, you would pay CGT at 18% on £15,000 (£2,700.00) and at 28% on £43,900 (£12,292.00). The total CGT liability would be £14,992. I have used the same allowances and tax bands but these ***** *****ge.
The costs of buying and selling the property (legal fees, stamp duty, survey fees, selling agent fees etc) can be deducted from the gain so they will reduce your CGT liability.
I hope this helps but let me know if you have any further questions.