The ONLY thing you owe your girlfriend is courtesy. You don’t owe it to her to foot her bills. Free yourself from that mentality. If you want to look after a woman, go and look after your mother.
If your girlfriend needs looking after, let her get a job.
Every money or gift you give to a girlfriend has no spiritual value to bless you. But if even you give your mother a cup of water when she is thirsty, that gift has spiritual implications that affect your material prosperity. Focus on your mum till you marry.