you may also need you and your mothers authenticated nso birth certificate and let her red ribboned it at our Department of Foreign Affairs so that it can also be a proof to the NAIA that you are truly related to each other as mother/son. you really need a salary certificate too and send it to your mother in order to prove to the NAIA immigrations officer that you can support your mother's financial expenses such as food,transportation, housing and other miscellaneous expenses while she is in qatar.