They had the following children:

• Jacob Hendrik (1 Dec 1910 - 1 Dec 1910, 's-Gravenhage, Netherlands)
• Stillborn son (1 Dec 1910, 's-Gravenhage, Netherlands)
• Jacoba Hendrica (17 May 1912, 's-Gravenhage, Netherlands)
• ? (male) (28 Sep 1914, 's-Gravenhage, Netherlands)
• Jacob Hendrik (9 Mar 1918, 's-Gravenhage, Netherlands - 12 Feb 2008, Bosch en Duin, Netherlands)
• ? (female) (4 Sep 1923, 's-Gravenhage, Netherlands)
• ? (female) (19 Jan 1925, 's-Gravenhage, Netherlands)

Notes:

• Pieter Paardekooper was bouwkundige, which possibly meant architect or engineer. His father was as well, and he was involved in the building of several of the W J Innemee & Zonen company's buildings. This first newspaper clipping shows that "Simplicitas" was moved into a new building in 1910 built by "Paardekooper" [2] .
• This second newspaper clipping is an article on the next move of "Simplicitas" in 1932, and the contractor is listed as "P Paardekooper". [3]. I found this same building in google maps, and here is the picture from streetview: .
• Witnesses at Pieter's birth: Dina Dentro-van Buuren, 62 years old, vroedvrouw, living in 's-Gravenhage & Johannes Martinus Geneste, 66 years old & Dirk van der Tas, 59 years old, both unemployed and living in 's-Gravenhage
• Witnesses at Cornelia Alida's birth: Hendrik Pieter Innemee, 36 years old, boekbinder & Dirk van der Tas, 64 years old, unemployed, both living in 's-Gravenhage
• Witnesses at the wedding: Wilhelmus Johannes Innemee, 28 years old & Christiaan Hendrik Innemee, 25 years old, both begrafenisondernemers and brothers of the bride & Abraham Paardekooper, 29 years old, bouwkundige, brother of the groom & Lodewijk Nicolaas Anton Orth, 23 years old, Tweede Klerk bij den Raad van Toezicht op de Spoorwegdientsen, all living in 's-Gravenhage

Sources:

1. Digitale Stamboom Den Haag. http://denhaag.digitalestamboom.nl/
2. "GEMENGD NIEUWS.". "Haagsche courant". 's-Gravenhage, 01-08-1910. Geraadpleegd op Delpher op 14-08-2016, http://resolver.kb.nl/resolve?urn=MMKB04:000138531:mpeg21:a0089
3. "BEGRAFENISONDERNEMING SIMPLICITAS 1887—1 Juni—l932". "Het Vaderland : staat- en letterkundig nieuwsblad". 's-Gravenhage, 31-05-1932. Geraadpleegd op Delpher op 14-08-2016, http://resolver.kb.nl/resolve?urn=ddd:010014150:mpeg21:a0007