You need to look for the
- marriage record of Alexandrina Palmire Henri/Henry. It should contain her place and date of birth.
- birth record of Alexandrina Palmire Henri/Henry at her place of birth.
- marriage record of Charlotte and Content Joseph Henri. It should contain their places and dates of birth.
- birth record of Charlotte Polain at her place of birth
- birth record of Content Joseph Henri at his place of birth
- marriage record of Alexandre Polain who married Charlotte?
All this records should be online for free on the websites of the relevant archives départementales.
If you don't know the places of birth or marriage you could look at geneaet or filae, but for filae you need to pay.
archives départementales de la Manche