Is it permissible for me to perform Hajj on behalf of my deceased mother using money I earned from working in a company owned by an Arab who sells alcohol and pork, knowing that my work does not directly involve alcohol or pork?

If your work is not connected to alcohol in terms of manufacturing, transporting, or accounting, then there is nothing against you. However, if your work aids in the consumption of alcohol, its promotion, its procurement, or supervising its accounts, then it is not permissible for you to work in it, and you must leave it immediately. You must seek out lawful provision for your mother to perform Hajj on her behalf. If your work is permissible, then your wealth is lawful, and there is no impediment to giving it to someone who performs Hajj on her behalf. But if your work is impermissible, it is not valid to use it in an act of obedience for yourself or for others, because Allah is pure and accepts only what is pure. It should be noted that Hajj and Umrah (definition) performed with unlawful money are considered valid by the majority of scholars, even though the doer incurs sin.