Yes, anything is possible. However, the probability is low. The size of Johor is about 3 times larger than SG but its population is about one third of SG. People seeking to buy property in Johor can always buy new developments, leaving little bargaining power for the older developments.
With the depreciation of ringgit consistently year after year (and compunded over years), the odds are further stacked unfavorably against home owners who purchase property in Johor using SGD.
If she rents a unit in Johor, the probability of her paying lower rent year after year will be pretty high.