If the community college offers the frosh/soph level courses that are accepted by the four year school for engineering majors, there is no reason why a student starting at a community college cannot complete an engineering major if s/he takes the needed course work before transfer.
To the OP: did your mother tell you a price limit?
There are a few different issues here.
a. What the OP’s mother’s actual restrictions are.
b. What the OP’s mother told the OP are the restrictions.
c. What the OP thinks the above are.
The likely cause of the conflict is that (c) the OP believes that (a) and (b) are different (causing a perceived lack of trust to go along with an oversized sense of entitlement), but it is not clear that they are. It is possible that the OP’s mother just assumed that any non-WUE school is too expensive, without actually looking into whether it is, and that the actual restriction really is just cost-based, rather than distance-based (note that WUE includes some very distant universities in Hawaii and Alaska). The OP should not assume anything about how much she is willing to pay – better to just ask and find out, rather than sneakily looking at bank statements and assuming something from that.