You may find it useful to obtain Iris's birth certificate. She appears to have been born Q2 1917 in Pontypridd registration district as this is the only birth of an Irish Price registered between Q1 1917 and Q1 1918. The record in question lists the birth of Iris M.Price with the mother's maiden name as Price.

If on freebmd you search Pontypridd births 1911 (when mother's maiden surname began to be listed) to Q3 1923 (when they married) with surname Price and mother's maiden surname Price , you'll get 49 hits, of which 23 were girls (including Iris M.). To determine which might be the fourth daughter, the following research strategies may work:

1. Check Birmingham electoral registers for when the daughters reached the age of 21. This will not work if they left home before they were 21, or if they died in childhood.

2. Order the birth certificates a few at a time, specifying that the mother's name must be Sarah Price and that the father should be one of: Samuel Beamand, name not stated, or a surname other than Price. The last two run the slight risk that there may be more than one woman of this name having an illegitimate child in this registration district in this period.

3. Wait until the 1921 Census is released. If the fourth daughter had died prior to 1921, or if she was living with other relatives, she will not be in the same household as Sarah Price. If, in common with the 1911 Census, mothers were asked in 1921 to declare the number of live births and the numbers of offspring living and dead, and if Sarah Price did not omit a deceased daughter, then you might establish her death. A comparison of Pontypridd registration district births and deaths in the relevant period, comparing names, birth dates, death dates and ages might narrow down candidates to enable ordering birth and death certificates, again with the stipulation to the registrar that only births to women named Sarah Price are relevant.

Good luck with your research!