There is only 1 Frank Horseman in Wycombe in 1911. Looking at Mr Beal's age I would suggest all the Horseman boys are his stepsons...............
BEAL, William George Head Married5 years M 26 1885 Chair Polisher Bucks High Wycombe
BEAL, Sushannah Wife Married F 48 1863 Bucks High Wycombe
HORSEMAN, Frank Son Single M 22 1889 Chair Manufacturer's Merchant's Porter Bucks High Wycombe
HORSEMAN, William Son Single M 17 1894 Chair Manufacturer's Merchant's Porter Bucks High Wycombe
HORSEMAN, Annie Daughter F 14 1897 Bucks High Wycombe
HORSEMAN, Florence Daughter F 10 1901 School Bucks High Wycombe
BEAL, William George Son M 5 1906 Bucks High Wycombe
BEAL, Frederick Son M 3 1908 Bucks High Wycombe
BEAL, Beatrice Daughter F 0 (7 MONTHS) 1911 Bucks High Wycombe
GRAY, Herbert Visitor Single M 25 1886 General Labourer Bucks High Wycombe