lol OP
there is nothing you can do!
unless the woman should start to reason you herself
but if you want the woman (which i wont advice) but ure a man

this is what u will do:

be extremely nice to the girl! do it so much that the mum will get jealous
when she starts noticing you because ure a sweet guy to her daughter
take the mother out, form i want to know your family to the girl
if you can be conversant with the mother (i mean freely) get her to talk abt her singleness and how she copes! let her know that ure there for her!
create a friendly rapport with the woman that doesn't involve her child, this way u become her friend! hence opening the road
now that ure friends with the mum,
to get her to reason you as a man for her:
you need to act really matured, use style to be hinting that you love older women
admire her looks then slowly after many days of praising enter her dress, then her cooking, then her ass , u have to be very cunning with this

now you need to put the tot in her head and allow her to get comfortable with it. matured women are very mindful of shame, so when you take her out dont hide or act ashamed make her feel as if she is ur woman! allow her to question your intentions and correct them herself (noo he is my daughters bf) in her mind and gradually get comfortable with the idea of you and her being together
now you need an awkward moment with her to trigger ur target, lets me just take it that she doesn't drink( will have be easier if she does)
when she is in ur car tell her to please change the the track of the cd playing, now since ure close to her that request shouldn't be weird
when she places her hand on the radio to change it quickly place ur hands on hers form teasing her that she doesn't know how to do it! place ur hand on hers on the radio and allow it to linger for some seconds!
if you dont have a car, you guys are friends take her for a walk at the beach then hold her hand! if she relaxes and doesn't take away her hand
congratulation you have won her!

You have a good script but you missed something.
Op need to know dangerous the daughter and the girlfriend are first
Sense nor go kill me