You're an MBA student. If you put together a successful application to a great business school program, you can also find ways to get funding.
Depending on how your allyship group is structured, charging membership dues can either be a convenient way to pool resources to maximize offerings, or it can be a major barrier to entry for those wanting to learn more about allyship.
Some groups have "tiered membership" in which non-members can attend some events, receive certain types of messaging, etc.
During recruiting season, companies are looking for ways to get in front of students. You'll want to reach out months ahead of time, but use this dynamic to form beneficial partnerships in which they can sponsor events or allyship group general funds. If you have print materials, put their logo on the back. If you're having an event, have a diversity and inclusion professional from the company give opening remarks. If you're having a panel, invite a woman of color from their company to join it. Make sure to closely collaborate with your Partnership Group to ensure you're not over-taxing existing relationships they have with the companies in question.
MBA Student government
Your student government probably distributes a fair amount of funds to different groups. Having a sympathetic person willing to go to back for you and find money in the overall budget can be a great strategy.
MBA administrators / program office
You'll probably want to try this option after you've already spoken with your student government. Find the best person to speak about funding: either the person who cares the most about allyship or the person whose job is most closely aligned with allyship aims. Ask what kind of a proposal would have the best chance of succeeding and make sure to get administrator eyes on it before the final submission.
Oftentimes universities have many different kinds of grants, funds, and contests that you could use. Spend an hour just googling, calling, and emailing university administrators asking about these kinds of opportunities. For bigger schools, there are frequently many options that would suit allyship programming perfectly – you just have to do a bit of digging.