Isobel named her firstborn child in her grandmother's honour. She did this because she missed her family and the magical community, which she had to leave behind when she married a Muggle man.
Minerva is the Roman goddess of wisdom and craftsmanship. Her Greek deity is Athena, goddess of wisdom, strategy, warfare, and craftsmanship. Minerva is less honoured than Athena and the warfare is left all to Mars, god of war.