Hi Kal,
She may have had a history of dating guys who gave her the impression that they wanted to ultimately get married, only to leave her after a period of time in which she invested a lot of time and energy in getting to know them and date them.
This particular girl may be rushing through the talking stage and giving you signals of marriage because she doesn’t want to put herself through the process of getting to know a guy over a sustained period of time and developing feelings for him, under the understanding that he is looking for a serious long-term relationship, only to have him leave her yet again.
She may be willing to take a chance on turning you off in giving signals of marriage this soon and possibly losing you as a result, than to put in the time on getting to know you and dating you, only to be disappointed in the end.