If you had made this plan at the beginning of 2023 then surely your Hajj would have been completed in this year by now. Because when the price of Bitcoin is 15.5K was the best time to invest, and now is the best time to reap the maximum benefits. There is still time to invest in Bitcoin, as there is a Bitcoin halving in 2024. If you start investing from 2024 then there is definitely a big bull run of 2025 where Bitcoin price is likely to increase to the maximum extent. So I think if you continue to invest from now and invest till 2025 then surely your mother will have complete Hajj money. It is guaranteed that everyone succeeds in investing in Bitcoin.
I agree with your mention of buying bitcoins to profit but look at his investment plan but he decided to invest in DCA method.If he had bought bitcoins at the time you mentioned and since then had invested in the DCA method, he would not have had much bitcoins.But if he could have bought more bitcoins at that time, he would have owned more bitcoins today.The purpose of investing in DCA method is to hold Bitcoin for a long period of time as investing in this method for a short period of time cannot expect the desired results.