Considerations for Joint tenancy with my Mom

[Emma S.]

Hi, my mom is going to come live with me & my kids (I'm a single mom). I'm currently renting. She will have about $150k from the sale of her house in a different state which is about 50% of the average house in my area. She wants to give me the $150k for a house in my name but it looks like there would be a gift tax in that case. How about if we bought a house together as joint tenants where she contributes the $150k as down payment and I'll be responsible for the monthly payments? I've read up on joint tenancy and it's perfect for our scenario since I'm sole heir anyway (no siblings) and absolutely no trust issues etc.
Question: What are the tax consequences now or down the road when my Mom passes away?